Sony Trinitron KV1541 Remote Set Super Hard Fix 1977 Vintage Color TV
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- čas přidán 29. 10. 2021
- diagnosis and repair of nice old television set
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If you are seriously interested in electronics diagnosis and repair especially solid state television, this is your video. Watch the whole thing and trying follow along
Shango066 I love how you got there and you break everything down I wish we had an electronic store like that out here very interesting and very informative video as always
What a kool Sony Trinitron kv1541 remit set 1977
Those plastic spacers are often found in transformers for magnetic current limiting. Edit: Thanks for seeing this through to a positive conclusion, very interesting and entertaining.
I wonder is the bracket that broke might have let the gap increase between the 2 core halfs, making the resonant frequency change. This is exactly why I don't like working on switch mode power supply's as they work with tuned transformers and they can throw curve ball's that can fry equipment.
Wow, got the house to myself and a feature length video to keep me busy... Nice timing man, thanks!
This 2 and a half hours are much more enjoyable than todays "blockbusters". Have a nice day.
I haven't been to the movies since 2001
Yeah because when you watch this videos you actually learn something that could be applied to everyday life and become useful instead of just filling your head full of nonsense and garbage actual real life skills and education far better than you could get in school or anywhere else in my opinion
Fuck them lame ass super hero movies !
Hollywood hasn't produced anything noteworthy since the early 2000s. It hasn't produced anything WATCHABLE since the 2010s. Let's face it this generation of Hollywood's tech driven vacuity is at least partially responsible...for driving user contributed content as entertainment on various internet platforms such as this one!
This video should be released in the theaters and dvd 📀
This video has all the hallmarks of a classic adventure move, suspense, fear, frustration and finally tears of joy at the sight of that raster.
As a kid in the 70s I hung out in a TV repair shop after school hours and got the tube TV repair bug. Sometimes I would carry an old surplus TV sets half a mile back to my parents house where I would tinker with them. I appreciate your videos and tenacity, really glad you didn't give on on this one, it would have been such a disappointment!
And stay through to the "end credits". That imitation of the giggle was priceless, as well as the '80s videos. Lots of Debbie Gibson.
still stuck with 21 inch toshiba crt tv, Age is 26 years and running.But the picture slowly losing sharpness.
I was a paperboy in 1988 or so when I got my first Sony Trinitron, a KV-1710. It was a rainy morning in April, ice caking on the TV, and it was in the garbage. I carried it from house to house as I finished my route, vigilant of the garbage truck. My arms were falling off, but I kept on saying to myself that it's a Trinitron. I got it home and defrosted it by letting it drip into the bathtub. A good clean, a good alignment with my TI-99/4A as the pattern generator, and that was my main TV until I was gifted a broken KV-1926. (Broken KV-1926? No stereo sound! KV-1926 was mono!)
My uncle [Moms elder brother] taught me radio and TV repair when I was age 8 -
and I am going back to (c)1950 -- Joining the RAF in 1961 - after learning to fly at age 13 -
Serving later with Bomber Command - I later studied Electronics and Electro-Mechanical Engineering,
having had a passion for it since a young age -
Having served in the Military for 30 years serving three countries, and the Government paid for all that education and other studies I undertook.
Well that was one reason in joining the Military
My problem now is that I know too much - Sometimes it can be a curse.
Even in my late years I find myself always repairing something - It keeps my mind active as does reading.
anything I can learn from.
One thing to remember - it is SONY and not Sony --
People look at things and like zombies they cannot see exactly what they are looking at.
Yet the clues are right in front of their eyes.
CORPORATE Names are 'Always' in the ALL CAPS iteration.
Names of living souls are in 'Mixed Case' Letters
Teach the zombies to pay attention to detail.
Good luck
Only a marketing or advertising person would notice such things. The ideas and importance of branding are only important to them, bean counters and the business owners. Whether it says sony Sony or SONY, it's all the same to Joe or Jane sixpack.
You ain't lying about the repair comments. Then people get upset when you don't have a quick answer for them.
Lots of entitled assholes out there
There are factory service notes, but only apply when the set was alot newer. It may still be a starting point. Now alot of of time has passed more parts have deteriorated. Thats why it's important to troubleshoot.
I also subscribed to your channel since Sony for me is one of the most difficult television units to repair! I do agree, sometimes to pay more attention and experience is more better since every failure has their reason behind! Some people also laid their questions to other forums and sites and sometimes, they may or may not work to the unit that we work, pretty like a gamble. I also remembered a quote, which said: "Perseverance is not a long race; it is many short races one after the other.", and using new parts to old units, feels more exciting. Oh how I wish I have an oscilloscope like what Shango066 did to that Sony, but overall very well video he did! And comparing a similar unit also helps, this technique still exist even in this modern day and age, say for example, in the world of LED TV repairs. But CRT TVs are pretty nostalgic, like those scanlines that LED TVs nowadays cannot replicate. Salutations to you and Shango066! Good day and joy from Philippines!
I'm only a third of the way through your video, but I'm already reliving the heartache of trying to fix Sony sets back in the 70s and 80s. RCAs and Zeniths never abused my heart the way Sonys did, eating fifty bucks worth of parts at the flick of a switch!
I have to repair an 1989 kv-m14e that has no power, wish me luck
@@Cesar-ot1xk Best of luck, my friend! Remain strong, and may the force be with you!
@@Cesar-ot1xk late 80's to early 90's was a particularly bad era for Sony. Replaced an innumerable quantity of SMD caps
SG613=POP! I went to a seminar back then for Sony where we learned how to troubleshoot using a floodlight bulb as a ballast
@@Cesar-ot1xk good luck!
2.5 HOURS of Shango? Holy crap, count me in. Dude, you're the master. I mean that. Yours is one of the 2 or 3 best electronics channels on CZcams.
Shango has a very clear speaking voice. I watched the whole thing at double-speed in 1.25 hours and understood every word.
Sure thing, and also repairing such a beautiful CRT witch (at least on the outside) looks straight out of the box.
Yes,, he definitely is a master, when it comes to electronics
Your Guitar amplifier stuff ain't so bad itself.
Yeah almost a movie, but dudeeee what a trip here with that cursed flyback, i mean isn't totally faulty, just out of the wack and surely is by that loose nut
Videos about the tv are more interesting than what's on tv. Thanks for the full length, must be a bear to edit
Those spacers serve two purpose: minimizing eddy currents, and preventing core saturation because flybacks and single ended output transformers are always driven with the same current direction, which magnetizes the cores if there is no air gup in the core it will saturate, it will develop 2nd order distortion and its efficacy will drop. To compensate these effects you need to use either bigger cores or you need to put in an air gup.
I don't know how the air gap "minimises eddy currents" because in the first place the ferrite core is a poor electrical conductor. (I'm thinking its a ferrite core, and not a pressed powdered iron core because the core had an air gap.) The gap in the core, created by the spacers... does prevent saturation by reducing the permeability. But the air gap also changes the inductance... and in a flyback, so the resonant frequency too.
@@willthecat3861 core saturation was the big problem with flyback low voltage derived power
@@GBS1043 Yes. Does that relate to eddy currents? Because the fact that ferrite doesn't conduct very much, and has very tiny eddy currents, means there is little losses from eddy currents
Just needed a little Flex Paste™ on that flyback that's all! No, seriously this was a real challenge and I'm glad you persevered with it. even if you probably did wanna hurl the set over the nearest hydrant! 😬
This could be a spoiler alert for ppl in the future. Idk but do something with this comment
Great video - RE 70s era on-screen display - I somehow convinced my Dad that we needed a state-of-the-art TV for football. And then I further convinced him that the only TV worth considering was the top-of-the-line Heathkit 25" - and this set of boxes with 1000s of components arrived. Got it all together, and the magic smoke stayed inside. It had an on-screen display and an ultrasonic remote. It had built-in test pattern generation. Our dog could hear the remote up close. Pop used that TV for 30 years. It was still working perfectly when it got replaced by a larger TV.
That was intense, i loved it! This long format stuff (even though it was a fight) is really educational.
Thanks for sharing
First time I’ve heard the f bomb go off on your channel. I’m with you man! Anybody who has rebuilt either an engine or repaired something electronic can identify with the “pucker factor” on start up.
Engines are easy.
Sony CRT’s are HELL!!!!
Man, what a great picture though. Nice work
Beautiful quality of picture despite the age!
Well shango066, Congratulations, you sure earned your bucket of oats on that repair! In the mid-1970's, that SCR horizontal flyback drive circuit became popular for a while. It put out a lot more power than the traditional beam power pentode and was needed to power the new high brightness CRTs used then. It proved to be very problematic, switching currents were so high, it caused RF to be generated, which broke down the plastic film caps used around the flyback. This circuit was replaced with a high voltage NPN power transistor in later sets.
These 1970's solid-state horizontal stages were hard to troubleshoot (as you well know) because, the flyback was also used as a power transformer to generate all the other voltages in the set so, the circuit ended up being a huge control loop, making it almost impossible to troubleshoot. You have to break the loop to do that effectively and run one block at a time.
That bad flyback appears to have a bad high voltage rectifier, that breaks down under full high voltage.
I especially disliked working on Sony sets. The company definitely has ego problems, always trying to reinvent the wheel and showcase their accomplishments, which ended up making the sets unnecessarily difficult to service.
In the 1960's and 1970's, it was common to see transistors misapplied in TVs, operating in regions that caused secondary breakdown problems. Over dissipating components was also common. That series pass regulator transistor for instance, it should be at least a 5 amp part and there should be some type of current limit circuit that folds back, instead of blowing the fuse and several expensive transistors.
The plastic disks between the flyback cores were used for two reasons: (1) To keep the core from saturating. (2) To adjust the resonant frequency to achieve the proper ring shape, which affects the horizontal sweep linearity.
I've seen some large current switching supplies from computers of that era based on SCRs too. Guess why we don't see those either anymore
@@gabotron94 Those SCR switched supplies came out before power FETs were developed. They were more lossy, generated more radio interference, and used physically larger coils/transformers.
The company I work for used to convert Sony Tvs into various types of video monitors, so we were pretty familiar with many of the different models back in the earlier days. The models that had the GCS (Gate Controlled Switch) were always a pain when they failed. Sony had a service bulletin that detailed exactly how to fix them, there was a list of parts to change every time a GCS failed and if their procedure was followed, 99 times out of 100 the set would come up with no additional problems. Many times the generic replacements would not work for the GCS as a lot of TV shops discovered. I used to do Sony work for five TV shops on a contract basis. The blown GCS was probably the second most common problem I saw, the most common was bridge rectifier failure to to lightning storms. As I recall, the GCS was something of a forerunner to the modern V-MOSTFET (invented by Sony years later). Somewhere, I think I have some technical info and specs on the GCS parts but I haven't seen it since the late 1970s.
For anyone working on later Sony TVs, Sony got the bright idea to put a large power resistor in parallel with the voltage regulator, to reduce some of the heat from it. If the high voltage failed, the main supply would jump to 170VDC which could sometimes cause other problems. Bad capacitors in the vertical deflection circuits were also pretty common. In later TVs, they used an integrated module for voltage regulation, some of these were awful, the main supply would vary over 10V just by turning the picture (contrast) control, this in turn would cause the horizontal size to change quite a bit. We would change them on an as needed basis if the change was more than 4V or so.
I actually have a pile of those heat sinks for the main voltage regulator, and maybe even still a box of the voltage regulator transistor that were removed during modification, at least several hundred last I recall. Still have a pile of Sony OEM replacement parts I should probably sell off too, including some genuine GCS parts. Last time I bought them, I believe in the 1990s, they were about $21 each. I think we still have all of the original Sony service manuals as well plus the service bulletins.
In my opinion, the 15 inch Sony TVs had the best picture, in part due to the tighter stripe pitch on the pix tube compared to the 17 and 19". The 12 inch looked great too. The generation after they stopped using the GCS circuit, which included the KV1205 were probably the best looking model of all, a bright picture, next generation Trinitron tube and much better color demodulation. While it is all hazy now, one of the reasons Sony TVs looked good to most people is that Sony altered the red channel decoding by moving the phase angle about 10 degrees more toward yellow to give a more orange red, which helped skin tones in the days of analog color demodulation.
Thank you for the entertaining look at these old televisions and the trials to repair them. Sony TVs stumped a lot of good technicians, especially the GCS models.
The ECG276 sub for the SG264 never lasted one minute.
Yeah, fixed a few Sony sets. High quality, but the circuit was always unusual. I suggested that they were designed by an alien, because if all other sets did something one or two different ways, Sony invented a third, like the GCS vs bipolar transistor for H Out. Very reliable until they got old, then you'd get a cascade fault and blow up half the set.
Wow, that one gave you a run for the money. Sometimes persistence is the answer. And I probably need some flex paste now. Roof and plumbing leaks will no longer be a problem.
welcome to the world of sony sets that use gate control switches it took us a long time to work out the idea of running the line osc from batteries we used 2 pp3 in series some sets used gcs as line output and psu chopper circuits they were a compleat nightmare antway very well done and thanks for not giving up
PS in the british practical teivision mag there was an artical about converting the line output stage to run useing a BU208a trasistor in place of the GCS.
Used to fix the odd Sony. Quality stuff, but it was very different. If there were three ways to do something, they did it a fourth way. i often suggested to the boss they were designed by an alien. Worked well, but GCS for flyback when everyone else used a bipolar transistor.... different design philosophy.
Good old times... Gorgeous stylish design!
Those beautiful Sony TV's and MTV was match made in heaven!
-And yeah, I need this Flex Paste ASAP!!!.. ;)
they may have been beautiful in their day and they also had a great picture for the time..but today? Other than being a collector piece, they're worthless. I have to admit, I bought a Trinitron Monitor in 1984 and finally gave it away a couple of years ago. I never had problems with it, but since the analog to digital conversion it was pretty much useless to me, even playing it through a converter. My other sets (modern LCD flat-screens) worked much better.
@@adotintheshark4848 -Beautiful design - TIMELESS!
-Even Industrial Design. Starting from electronics like this Sony, it slowly came into our life and became the norm - like everyone's 1992 Ford Taurus or Nissan 300ZX... -Still beautiful even today - no matter of specifications!..
IMHO
Watched the entire video, outstanding. 30 years ago I worked on thousands of these analog masterpieces. It was always a challenge I miss those days. Best Regards keep up the good troubleshooting
best 2 hours 26 minutes of my hungover saturday, a real trip
Great stuff Shango! Yes, these are a pain sometimes. What do you think of the two series HV diodes to the CRT anode, possibly leaky? Maybe breakdown in the H-STAT block? Thanks for taking the time to share your adventure.
I think it has something to do with the broken bolt because it comes up again in a future video. If I can find a replacement u bolt I might revisit this
@@shango066 I used to do Sony repair for many years, Many MANY years ago. Smells like the h-stat block to me.
I also have to say, Sony sets from this time period are what made Sony famous. Their picture quality was so far ahead of everyone else's, and the engineering and circuit design was like 5-10 years ahead of what the old established US brands like RCA, Zenith, and Maganovox had.
@@shango066 the bolt presses both halves of the ferrite core tightly together to keep the air gap (thickness controlled by the plastic inserts) small. When the pressure is missing the air gap will increase, greatly reducing the inductance of the flyback. Your Sencore instrument read 1.something instead of 10.something µH !
@@shango066 I think that will affect the inductance of the flyback a fair bit. Think of the way a shading coil affects an induction motor.
Much better than the crap Hollywood has been putting out the last 8 years. And the best bonus is your take on society. Thanks Shango001 for making my entire weekend and take care!
Much better than the crap Hollywood has been putting out the last 8 years? More like 35-40 years. Once they started coming out with really bad TV repair videos like Deep Yoke and The Texas Instrument Microcomputer Massacre, I just gave up on movies altogether.
I worked on many Sony Trinitron solid state sets a few decades ago; they were one of the most difficult TV's to work on. They were well known for cascade failures, the most common failure, the regulator, SCR Horizontal output, and the occasional flyback transformer, that caused even more parts damage.
Hi Shango, I would like to present some information toward correcting the defective transformer issue shown at 1:38:XX and 2:03:XX of the video. You mention that you will be working on another Trinitron in future episodes. I hope this information is not too late to try.
First I believe that the broken U bolt that holds the cores together is the root cause of the flyback converter misbehavior. Equal pressure is required on both legs of the core set to maintain an exact air gap between core halves. Those plastic "tiddely-wink" buttons glued to the core halves provide the approximate gap length. They should be equal in thickness to prevent stress on the ferrite cores. When being manufactured, the primary inductance is measured and adjusted to give the correct value plus some tolerance using these plastic gaps. Sometimes the primary inductance can be modified to tolerance by torqueing both nuts on the end of the U bolt. The broken U bolt was likely over torqued and was perhaps an attempt to get the correct inductance on the production line.
Second, The reason why the gap is important is that the gap enables the flyback transformer to store energy and as mentioned above, sets the primary inductance. The primary inductance sets the flyback operating frequency in self oscillating flyback converters. (Im not sure, but I think this is the circuit used here). Having pressure on only one part of the core causes the other side to separate further apart thus reducing the primary inductance and allowing additional energy to be stored. The flyback switching frequency increases and the additional stored energy has no where to go but burn up the 39R snubber network.
To test this, take the known working out-of-circuit flyback transformer and measure its primary inductance. Hopefully you can measure this at 10kHz. Note the value, then measure the defective flyback transformer as situated with one part of the U bolt tightened. You should see a measurable difference between the two parts. Now apply equal pressure to the defective transformer cores using a pair of c clamps over the ends of the core. Pad the clamps so as not to break the ferrite material.( I use those "Quick Grip" mini bar clamps.) You should be able to dial in the correct inductance. In fact, you can see the effect of the primary inductance if you just pull the core halves apart...just for fun. If the primary inductance remains low, you can sand off some of the gap material equally until you achieve the primary inductance of the working transformer. To finish the mechanical mounting of the transformer, you may be able to locate a U bolt for the core set, but it may be easier to locate 6-32 brass threaded rod. Use a piece of aluminum plate to distribute the force of the torqued brass rods on one face of the core set. Dial in the inductance and give it-a-go in the set. Thank-you for your many hours of technical mentoring and humor thrown in for good measure. Cheers!
It's turned into a common problem with these sets. I'm sure you're right I just don't know if it's worth the time to try and figure it all out and dial it in
The resistors had been changed on the flyback on the "Modified" TV to increase the brightness as it was used as some form of rear protection display.
Brilliant video, really enjoyed this one.
Sony rear projector, I have been inside this TV in the mid 80s. Video gave me PTSD.
The two flyback powdered cores are separated by a insulated disc between the cores... This tunes the flyback... The broken nut holding it all together would allow the resonate frequency to change because that gaps are too far apart...I just saw the two discs (red/black) ... Tuning the horz freq...
I don't think its a powdered iron core because the core was gapped. (Powdered iron cores already have a low permeability.) Anyway... yes, the size of the gap would change the inductance, as so the resonant frequency of the flyback. Also since the gap affects the permeability... for a given drive... decreasing the permeability would affect the energy stored by the flyback.... I believe gapping the flyback core increases the amount of power it can produce.
The dreaded brown glue, which eventually conducts. The removal of that gunk is essential, especially if it crosses two component leads and/or it's smeared on the solder side of any of the PCB's. That stuff was always a nightmare and was the cause of many failures in TV's, VCR power supplies and computer monitors... Good catch on the flyback transformer and the fixing of the vertical... WELL DONE!!! 10/10
Yes! A Full Feature length Shango movie!!!
What a ride! Grew up with trinitrons and still have a broadcast monitor in near mint condition. Never giving up can, no doubt, have its own rewards. Thank you!
Well.. as the old saying goes: " When the going gets tough..." A truely brilliant and excellent video ! Thank you for all your work and efford you put into this... wow... I guess people who hasn't worked intensively with electronics for years and years haven't got a chance of imagining, what you've been through to nail this one. The 150 minutes of video is just the sugar on top in a process like that. WELL DONE SHANGO!!
Imagine a client brings this set to your shop some time in the '80s. You have: no documentation, no donor set, no working set to compare to. There is no google to find out the specs of the failed parts. At every test run you burn a day wage worth of parts. Good luck to find an error which is not measurable even with that specialized instrument which cost a fortune back in that time, so really a few could afford to buy it.
Shango, thank you to post this video and pointing out, how clueless are those "what could be the problem" questions.
Kind of like an automotive tech digging into a BMW without the tools or manuals!
What can I say "It's a Sony"
imo best video you ever made. Sony really had some weird and bad design decisions back then. I'm a educated radio/tv techniciian from the back in the 80's and I'm glad the shop I worked in rarely saw Sony tv's. 😁
Thank you Shango. You deserve a break now. 😌
Back in the day my friends Trinitron was always in the shop. They were always called the best TV. I guess they were when they were working.
@@rogersmith7396 These things arriving at the end of their reliability bucket curve and filling the racks in the workshop.. plus new management policy of "you blow it then you pay out of your wages" meant I quit the TV business and went off to eventually end up being a live sound engineer looking after huge sound rigs out on the road.
It's surprising how easy it is to repair these modern flat screen things.. but there is no trade left.. *cough* 470µF 35V *cough*
"You could burn money faster in this than in a fire" Brilliant line! Been there with an Australian Sony KV-1830AS that had a sg-613 in it. They were AU$50 a throw back in the mid 90's. At the time I only had poorly photocopied schematics and no youtube videos to help.
Another fun Trinitron to fix is the KX-27PS1 Profeel monitor (which I had and absolutely loved). I has a weird self oscillating SMPS that controls the primary side by injecting a signal from the secondary side of the isolation transformer. My one would intermittently kill the SMPS switching transistor on power up. After replacing the main switching transistor (2SC-something cant remember) many times I modified the soft start circuit which finally fixed the problem.
Oh yeah, I blew up a couple of big and expensive IGBTs (and fuses) when trying to repair my UPS until I managed to do it.
I come for the commentary especially when the news is featured after a repair but it's also interesting seeing how this older technology worked. As an engineer who works on modern tech it amazes me what people were able to do 40+ years ago without microcontrollers and processors handling most of the circuit logic.
It amazes me how modern techs believe digital is not virtual and we were not able to do things before the virtual world 😆
Wow, this is the master class of troubleshooting! Worth every bit of 2.5 hours. More twists and turns than any crime movie I've ever seen.
Answer to fixing TVs: well with dead TVs its simple, it has to be the on / off switch. How do I know? Because 9 times out of 10 the customer would tell me so, Its completely dead mate, the on / off switch is broken :-) I kid you not, when I was fixing TVs many years ago, if I was told that once, I've been told it dozens of times. Keep up your good work my friend, you really are devoted and the lengths and efforts you go to never cease to amaze me. You have an excellent you tube channel and a very comprehensive knowledge, I am nearing the end of my life in this world and I just wonder, I'm sure people will, look back at your video's and gain an awful amount of know how from every thing you've recorded. Keep it up mate. your you tube channel is the best.
All along the video I was yelling at the screen: "The U-Clamp...the air gap...the reluctance!" 😊 Seriously, one of your best videos to date, excellent troubleshooting, astounding perseverance and a good reminder of the dark Trinitron servicing days where we often fitted a new flyback into the Sony magic electronic marvel boxes just to be on the safe side, haha. Huge thumbs up, thanks for sharing👍👍
Very cool, did you know that from experience? Or did you spot the broken bracket earlier?
Just goes to show how these are still "analog", even though there's transistors it's still a bunch of tuned circuits working in harmony. Thinking of it that way makes it easier to understand secondary and "chain" faults like this...
Hello Where in the video did you see a broken bracket please?
It's great how you can capture the frustrations of an electronics technician in a great video, this is so recognizable!
Great from start to finish, thank you!
This was a glorious and brutal repair. Thank you, Shango, for this. May we learn from you.
Watched the whole thing through. Fantastic repair and I admire not only your determination but your insistence on knowing why each part failed, such as the flyback.
I’m glad I’m not the only one blowing up new components when I’m trying to repair something. I’m glad you didn’t give up on it and you got it going just like I knew you would.
The shot at 1:34:56 with the resistor glowing reminded me of the actual footage shot from the helicopter of the Chernobyl core glowing.
Thank you for such a remarkable video. Watched the whole thing in one sitting and enjoyed every minute.
I watched it all the way through! Thanks so much for taking the many hours and days it took to make the video, without people like you keeping the history alive, it would all end up at the bottom of some land fill site never to be heard is again. Well done.
Thanks much for taking us along for the ride and even more for your hanging in there when most of us would have given up.
THAT was a seriously good video, thanks Shango! A good Saturday morning well spent. 🙂 When you started taking about that C1810 transistor, I went digging through my old ones I've accumulated to see if I had one to send you. Didn't have one, but then I've not torn apart any Sony's lately.........of ever, they were always worth fixing. 😉
I'm wondering if the broken bracket on the flyback is the issue. It appears that the spacers between the two ferrite halfs are soft (compressible), and an airgap is needed. From what i understand, the size of such an airgap influences the performance. Maybe that whole darn thing is somehow adjusted/tuned by tighetening the screws for that bracket, thus effectively adjusting the size of the airgaps? I mean, if the psacers would set a fixed airgap, why go through all the trouble with a threaded bracket and nuts, instead of just gluing it together and mounting it with a simple clip?
The air gap has a lot more reluctance (resistance to magnetic flux) than the ferrite (if that is what the core is)... perhaps 10 to 100? times more. So a bigger gap... more reluctance. Usually the air gap in flybacks is set very precisely, and is usually there is glue, so the gap doesn't change.
I read in a TV repair book decades ago that the resonance of the flyback is tuned in the factory with a certain amount of air gap, and the brecket is also part of the tuning, IIRC it acts like a magnetic shunt, so it being broken definitely messes with the resonant frequency. The flyback is tuned for self-resonance at around the third...fifth harmonic of the horiziontal frequency, so it's very picky for tuning.
Your right mate, all fly back transformers have to have a gap, this is how fly back transformers work, inducing big reverse voltages without the core saturating, and the size of the gap has big effects on efficiency , but I doubt very much if the gap would be adjustable, I can remember them coming lose and clamping back up fixes them, forward type transformers don't have any air gaps, But hey, what would I know, been long time since I got into any technical stuff. But you just have to shake this guys hand, for his perseverance and efforts, way beyond any thing 99.9% of people would even think about, I know when I used to fix TV,s (70s 80s) at best it would have been change line output transistor, and maybe few before it, and if no picture it would have been beyond economical repair and it the parts pile :-)
Incredible amount of determination on this one. I love the stability of these old Sonys (once you get them working). I don't care if it's a year ago, you nailed a really tough one.
I became a catholic living in Chile listening to local radio and you probably, learning to understand what they say on Channel 6, while repairing old televisionsets
That lovely thing is actually a GTO or SCS which is similar to a Thyristor or SCR except you can turn it off by applying reverse current on the gate. If it would be a regular Thyristor or Triac to turn it off you'd need to interrupt a current flow through it.
Best damn electronics repair channel on CZcams.
yeah it is, when he dosent b-it-ch about coooovid va-x
@@oldcarnocar 😂
@@oldcarnocar Yes, agreed, or veer off in the weeds into politics. Then it's a slippery slope downward.
@@herbertsusmann986 yes
@UC_msXp5wQLwUXx5nE4cUEEg vaccines are for pussies
My parents and grand mother had the exact same set! Sure brings back memories!
This is complicated "stuff"...and I am amazed that you have the patience for it! Thanks...with respect!.
Perfect timing for the notification, just as someone wanted to use the system to watch two college teams from Michigan chase a lopsided ball and roll around on the ground, c'mon man, you gotta be kiddin, Shango just dropped a new video!! (No screaming at the screen at my place today.😁
Hey I only posted this once why is it on here twice CZcams? Man-in-the-middle? Vault 7?
The Flex Paste is a malleable butyl rubber compound and that is some good stuff.
I truly love all your video's , I always hit like, not only expert repairs but your honestly more entertaining than any tv program could hope to be, Thankyou :)
Man, I watched this entire video. Nice work, and you’re very entertaining to listen to as you work your magic.
at 2h 4m Air Gapped transformers are quite common those shims are actually for tuning yes, I suspect the transformer may have an internal diode that is shorted aka built in tripler diode circuit that's shorted which wont be easy to diagnose.
Maaaaan, you just ran into a thyristor based horizontal output!
These things are known to be really hard to fix. Good to see this job had a happy ending.
No wonder why the SCR was fried at 1:12:32, the flyback was meant to be driven by a GTO (Gate Turn Off) thyristor. The SCR latched in there
I do remember the actual Sony service info around this time did say to run the oscillator off battery supply or an expensive bang was on the cards.. Somebody asked me about fixing one of the big KV series things last year.. simple answer.. NO.. I don't ever want to see one again..
Just re watched this as not seen in a while. I forgot just how difficult this set was to bring back. Serious patience required for this stuff, was a good job you had some willing donations from the spare sets.
Huh, what a journey! Thank you very much for hard work and knowhow mr shango066. 👍
Incredible incredible video. Shango, you’re a goddamn genius.
Great job, you're a Master for me! This is absolutely the most interesting 2.5 hours of electronics repair I have seen on YT! Greetings from Poland !
I watch your vids on my tv on youtube watched whole thing not electronic expert just dable on minor repairs great job Thanks Ron
Very well done Sir!
This sort of effort really has to be admired.
Very nice job. I used to hate it in the mid 90s when I got a Sony in for repair. I had 3 or sometimes 4 separate current limited power supplies running at once to keep from blowing up those expensive transistors. Never saw one with a bad 17V Zener though and that flyback was just weird. It has to be that difference in timing, 11 on one and 1 on the other? Internal capacitive reactance due to internal lack of insulation between windings maybe?? Very enjoyable 2.5 hours and I really felt for you a couple of times. Been there.
Q: I have this TV that just hums
A: Aaah that sounds like a leaky zener in the horizontal and maybe a faultless but defective flyback.
Admired your persistence on this. I also appreciate the much lower cost substitution parts callout. Well done!
That is one sleek looking TV! Glad you were able to save it!
Shango, if you have a TV with problems in the horizontal deflection circuit, its never a good idea to apply full B+ and hope for the best. What you can do instead is to apply 10 or 20% of the B+ voltage while measuring the collector retrace voltage on the HOT. This way you can check if the retrace voltage stays within the safe operating value of the HOT. If the deflection stage works fine, then the retrace voltage will react proportional to the B+ voltage. If it doesn't then there is an issue in the stage and is a good indication that if you apply full B+ you will likely destroy the HOT. Some TVs might not start the horizontal oscillator if B+ is not within its operating range so in this case you are going to have to feed the HOT driver stage with an outside pulse to test the horizontal deflection stage. You could try to make a video about this procedure is very useful and I haven't seen anyone on youtube. Also, excellent video!
The fun part is, lose horizontal drive, the SCR is on and stays on, thermally running away and shorting.
With the Sony gate turnoff SCR, if you change it, replace the damper diode.
I think the flyback core being isolated in two parts could be intentional. Modern switch mode transformers NEED an air gap in the E-Core. Perhaps this type of flyback too needs that air gap?
I appreciate you bringing us along on this adventure! :P
Much respect for your persistence. Wow! This was really a tough one!
Wondering if that wire bail/bolt through the flyback is required to complete the 'circuit' around the core since it has those insulating spacers in it. Would've probably tried using a bolt from one of the other sets to see if that might bring it back into 'spec'.
Always hated working on Trinitron sets, seems like they stuffed the set full of 'Black Magic', and one little fart in the operation would pull the pin on the smoke grenade...
That is a possibility and it comes up again in a future video.
Flyback cores always are gapped.
Hence spacers.
Increases magnetic saturation / reduces Al value.
Man those are some mind blowing circuits.... LOL Cool to see you
work on these sets. Cheers! 🍻
Love your content. I was a two way tech for 30 years (not many tv's) but enjoy your videos for everything you do.
Mike
The amount of time AND patience you put into putting this video together is beyond words! Yes, I did watch all 2+ hours of the video too. You have my respect! One question - will Flexseal hold up to an EOL TV??? 😉
There's only way to find out, isn't there? :)
I don't know but i have a broken toilet tank and would surely love this. I'm not in America so its nearly impossible to get, hope to find something similar. Also a crt with some burn out stuff is no reason to throw it, Americans are so spoiled, but crts are now gone.
The flyback transformer requires airgaps whilst an SMPS forward converter transformer, does not.
"To make sure lumesponder is lumesponding" -- this is my most favourite author of all youtube now.
An epic video full of anguish and suspense. Overcoming defeats and setbacks, the hero is victorious
Gotta give you credit for sticking at it... The SCR horz outputs used in Sony and RCAs could bankrupt a small service company... I think the flyback was damaged after the zener (original cause of problems) failed by another tech trying to tightening the nuts...
Beware of the brown glue on the electrolitics. As it ages it becomes conductive; nasty stuff.
Yeah, I noticed that as well. But it appeared to be used sparingly, so it didn't touch two leads.
Verily agreed! Reminds me of what Retro Tech, Jordan Pier and Radiotvphononut said about these nasty glue stuff... Something with aging and chemical components made them conductive so sometimes it is best to get rid of them if the colour turned like on this video! The key is those leads not to get into contact with those nasty glue)
I love your videos. I am so glad I have a long one to watch this week. I learn a lot and your comments constantly entertain me. Thanks, I appreciate your time and knowledge!
I came here for the flex paste ads. Thanks shango. If you hadn't fixed that TV, I would have never known of a boat made from such a product. This is the future.
My TV turns on and works perfectly, how do I break it so I annoy you with a diagnosis question?
EOL videos can help you.
A common fault the h. o/p breaks down between windings under load & cooks o/p thyristor which triggers the fail safe n blows the zener (hence thats why its highlighted) then the reg goes s/c, I fixed Sony's for 25yrs so I've seen this before, it's how the fail safe works..basically it nuc's everything to stop a meltdown.
I use love fixing TVs all night long on the tough dog, good days I remember. mastery of troubleshooting.
When I was in the I.T. industry I used to have all manner of people throwing out those "my computer does _______? What is wrong?". My typical response was "It sounds like you over torqued your bindle rotor and need a new 3/4" pinkney flange". More often than not I'd get a very enthusiastic thank you and they'd go off on their merry way.
I wonder if the two core halves of that bad flyback got a little loose from being used with that broken metal thing that's supposed to hold the flyback to the chassis. (depends on if it was used for a extended period of time with it in that state). Maybe it helps keep the two halves of the core together. (even though the glue is supposed to do that but maybe the glue gets a little soft from the heat from the many hours the TV could have seen). That or since it wasn't properly attached anymore mechanical movement of the flyback from the loose side caused the cores to be pulled part ever so slightly. This would mean the tolerances for that spacing is very tight so it wouldn't have taken much to throw it off.
The spacing of the two core halves changed and that's what was causing the issue? Just a random guess from someone who doesn't really know how flybacks work though. So take it with a grain of salt. :P
Hi ApacheThunder, I really didn't expect seeing you here !
Didn't know you were into electronics too.
I really love your work and idea's on BF1942 modding, SSM and maps :)
Greetings from Holland,
Raoul (playername: TheoNeo),
Server admin of The Drunken Mug
I knew some "old school" TV repairmen and Sony was the one brand of set that they would not touch. As far as the bad flyback, I may be way off base; but, I wonder if the internal HV rectifier diodes are leaky or shorted? A few times, I've had a flyback pass the "ring test"; but, would not work in circuit and bad internal diodes is what I blamed it on. In the early '80's, RCA had flyback issues that turned out to be caused by RCA skimping on the number of HV diodes used inside of the flyback (resulting in diode failure). The replacement flybacks corrected this issue. Oh, and I made it this far in the video.
You all right !
shorted intergrated flyback diode is a fun one. you can get around it by patching a new one half way down the anode cable and the TV will spring back to life. Unfortunately the entombed diode will slowly turn into a heating element and burn a hole in the plastic.
With sencore VA 62 first ring the fly back if ok drive it then measure the anode voltage.
I was holding my breath at the end after you got it going. For those who have done an involved repair with expensive parts will know the feeling.
Super helpful video. Really appreciate you taking the time to do this one and the things you taught us along the way.
Been through this with these Sony gate turn off SCR circuits, everything must be perfect or kiss the SCR goodbye, use only Sony original scr's ,replacements are unreliable. Sony only seemed to use this miserable circuit for a very shot time before going back to bipolar output transistors.
His customer is a sadist, they want to see shango suffer.
But it was'nt a Philco Pedestal.
Man, I think of all the videos that I've watched from you, this had to be the toughest diagnose. I'm glad you kept up on it rather than let the TV "win" and have that determination that "I'm going to fix this thing!" Well, at least you got it working again so I can discover the amazing world of Flex Paste. This video was an enjoyable watch!
Nice fix, reminds me of a late brand new Mitsubishi set that came to me. It had fried the flyback transistor, control IC and several components in the PSU. Replaced all of the damaged components and checked for obvious problems etc. Turned it on and was greeted by a perfect picture. I thought 'brill, that's sorted'. After running the set for a few hours with no issues, turned it to standby with the remote and there was a bang! All the components that I had just replaced had popped. Turned out that, from the factory, there was an inductor missing from the snubber circuit. The fault would only occur when the set was turned off and the fields collapsed causing a back EMF spike through the flyback circuit. Took a bit of working that out.
I wonder if Sony repair centers had "Sony-specific" test equipment, or if their techs went through the same type of hell that Shango did, in bring this set back to life?
Well I think things often fail in a similar matter and those failures are documented by the manufacturer and likely to be the first things to be looked at during repair and those common problems are ironed out in the yearly iterations of the product.
Sony might of just thrown parts at it till it worked, "that resistor is burnt!" Replace the board!
46:00 Burned away fifty bucks, Sony Smoke-o-tron is really an econoquick stuff, it's quick and it's an economic disaster.
I just knew you wouldn't let this set get you. Congrats on a super difficult repair!
Awesome troubleshooting work, sir!!
Thanks for the trip back to high school at 2:21:58... on a style of TV we likely would have watched these 80s videos on MTV when it was a video channel !!