Can this sad broken C64 be saved?
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- čas přidán 21. 12. 2019
- This Commodore 64 main board had so many things wrong with it, it was a fun challenge to get it working again. Previous owner(s) had caused damage to the board by removing chips, which adds an extra layer of difficulty to troubleshooting. It all starts with the dead test cartridge doing nothing.
In this video, I show my techniques for troubleshooting and fixing all of the problems.
--- Video Links
Special thanks to IZ8DWF who has given me great advice on repairs:
/ @iz8dwf
C64 main board schematics:
www.zimmers.net/anonftp/pub/cb...
Diode Symbols:
www.rapidtables.com/electric/...
--- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/s.nl/it.A/id.16...
Jonard Tools EX-2 Chip Extractor:
amzn.to/2VazxDS
www.jonard.com/Products/EX-2-...
Wiha Chip Lifter:
amzn.to/3a9ftWw
www.wihatools.com/precision-c...
O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
www.rigolna.com/products/digi...
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
amzn.to/2wG4tlP
www.aliexpress.com/item/33000...
TS100 Soldering Iron:
amzn.to/2K36dJ5
www.ebay.com/itm/TS100-65W-MI...
EEVBlog 121GW Multimeter:
www.eevblog.com/product/121gw/
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
www.ebay.com/itm/USB-Logic-DS...
Magnetic Screw Holder:
amzn.to/3b8LOhG
www.harborfreight.com/4-inch-...
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
www.ebay.com/itm/14-16-18-20-...
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
www.retrotink.com/
Plato (Clone) Side Cutters: (order five)
www.ebay.com/itm/1-2-5-10PCS-...
Heat Sinks:
www.aliexpress.com/item/32537...
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Links
My GitHub repository:
github.com/misterblack1?tab=r...
Commodore Computer Club (of Portland, Oregon and Vancouver, Washington)
www.commodorecomputerclub.com/
Tivoo Pixel Art Display seen in my videos:
www.amazon.com/Divoom-Tivoo-r...
--- C64 Stuff
JaffyDOS:
blog.worldofjani.com/?p=3544
C64 Test Harness I use:
• Building a Commodore 6...
C64 Homebrew cartridge PCB: (used for the DeadTest / Diag Cart I use)
www.ebay.com/itm/Commodore-64...
EasyFlash 3 Multi-Cart:
store.go4retro.com/easyflash-3/
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music by:
Nathan Divino
@itsnathandivino
Outro Music:
Abyss by | e s c p | escp-music.bandcamp.com
Music promoted by www.free-stock-music.com
Attribution 4.0 International (CC BY 4.0)
creativecommons.org/licenses/...
--- Image Credits
None - Věda a technologie
Well, it's nice to see that C64 finally fixed. I had given up, and after watching that video, i'm sure i'd have never gotten it fixed on my own, so thanks! I have a Zener diode to fix that cassette port from a (would you believe) worse parts board. Also another SID chip (I might have put the flaky one i had in there because I didn't want to risk a good one in that board). Just need to track down a PLA chip (or PLAnkton).
Go for the PLAnkton! I have one in my original C64 from '83 and one in my SX-64 and they work wonderfully, and run very cool. I would never again want to use an original-type PLA chip when they are basically time bombs.
Agreed. A PLAnkton runs colder, doesn't die on you and has the potential to outlast the C64 board :)
Adrian has something he's testing that might be a cheap alternative to pla's or Plankton's so I'm waiting to see how that goes.
@@brianv2871 I'll be waiting for the magic Bell Icon too. I'm really interested of anything able to replace a PLA
@Jayson Cowan at this stage of the game we are well past the early on point that’s for sure. 37 years and still locating working ones is getting harder and harder these days.
This is one of those videos where about half way into it I wonder to myself: "Why on Earth am I watching this, I have never owned or will ever repair a Commodore 64 computer." Then it dawns on me, just like when I watched a guy construct a scarf joint on a large wooden beam....there is something very satisfying about watching true masters work at something, and continue to work on it until it is done. Okay now on to watch some glass blowing expert. LOL.
same, though i did used to own a c64 (even into college!). i would never repair one, but it was just super engaging to watch the mystery unfold
I actually could have written this comment!!
I strongly agree :)
I'd recommend to you channels about renovating old metal tools and knives.
I work on domestic gas equipment (boilers, fires & cookers etc) in the uk. I’ve always been fascinated/interested in computing and owned a ZX Spectrum (amongst others) back in the day. I would love to get into this sort of thing but wouldn’t know where to start. I frequently use a multimeter for working on boilers but this is a whole different skill set.
"total novice" is being way too hard on yourself - this is some 'level 7 - chip ninja' stuff you are pulling off. very impressive and well done for your tenacity in getting it done.
Anyone who can repair that thing is not a total novice. This was a ton of work that needed know-how, investigation and skill.
experience trumps training anyday.. a few minor things would have helped with formal training, and knowledge of failure modes, but they would have saved a few minutes at most..
training makes gaining experience slightly less painful.
Novice?! you have scopes laying around AND a bald head! That pretty much makes you god mode by itself 😎
Someone having an oscilloscope and using it to test the chips ain't a novice :) Novice is someone like me only using the solder iron or doing some point-to-point tests :)
Have to agree. You're definitely above the Novice stage. More like Advanced.
This is better than watching a TV drama - so many unforeseen twists and turns as the narrative unfolds. Puzzle logic is indeed fascinating.
Wow, I've just sat here for 40minutes not knowing what the hell was going on,but utterly transfixed😃
yeah, me too. I just wanted to see if he could get it working again. pretty amazing to watch actually.
Hahahaha me too! I love watching electronics repair videos, but have absolutely no bloody idea what it going on
same here
Guys, there are good electronics tutorials on the web, you might want to check out www.electronics-tutorials.ws/ or simply throw into duckduckgo.com the words "electronics tutorials". And you might also want to get familiar with the Arduino IDE (implies also learning C++), which allows to program many different microcontroller boards of different architectures (AVR [e.g. ProMini or ProMicro], ARM [e.g. STM32F103C8T6], or some wi-fi connected ones like NodeMCU ESP8266...). You might also decide to put that together with what you learnt in the electronics tutorials and design some extra hardware to use with your microcontroller board, you'll have to test it on protoboards and then maybe use KiCAD to make a PCB (you might buy a budget oscilloscope like Hantek DSO5102P and a KKmoon dual channel signal generator, both great value for the money... or maybe something more expensive).
I've come to watch this one because I have been a C64er for quite some years, also doing some assembly coding on it :D and of course I remember some great whole-summer-night videogame sessions with my brother, we are now living in different continents.
me too, im bamboozled
It's fantastic to see how much love these old machines still get almost 40 years later. I just found my original C64 again after "losing" it for decades.. :-)
CZcams; "Yo, you like electronic diagnostics and repairs?"
Me: "Well, kinda."
CZcams: "Then just look at this, yo!"
Was not disappointed.
I have two solid years of electronics training and over 30 years of experience, and know very little about the C-64 inter workings, I own two, and used to program them in Commodore basic. You did an awesome job of troubleshooting the board, and had real tenacity in diagnosing each and every problem. You have better patience than I do. Very well done repair and video. I learned a lot about the C-64 watching your video. Thanks!!
Hi Adrian, I am a former owner of C64. I used it to create my college papers while I was attending the University of Guam in the 80s. It ran fine until the monitor was broken and I did not have your channel back then to learn how to fix it, so I threw it away all together. Watching your video took me back to thirty-eight years ago. Thanks.
Hmm, I only have a tip for you, when dealing with bad sockets and chips, cut the legs of that bad socket or chip, then use a desoldering iron vacuum pump. Lets you get rid of each individual leg of the socket or chip without putting much stress on the pad and trace. Just a tip, not a must.
I am an electronics engineer and I think your troubleshooting was just fine. I liked that you used the scope. I am not sure I would have done as well as you. You're very experienced in debugging c64 hardware.
If someone says, "it's fine" TEST it anyway.
My mother said the radio of their stereo system stopped working. So I Ebay-ed them a replacement. When I finally went over to my parents' place this Xmas, it turned out the radio was perfectly fine and instead it was the amplifier that had stopped working :) So yeah, never listen to other peoples' diagnosis ! Her comment: she calls the entire stereo system " the radio". Cheers, mum :)
@@Baerchenization I worked in the computer hardware repair industry in the 1980's the first lesson they taught us was:
Listen very carefully to what the customer thinks the problem is and what they think will fix it..after the customer leaves ignore everything they just told you...
On side note our troubleshooting skills in hardware repair was make sure you have good power to the board then start at the CPU checking all input and output signals and work from there..we were lucky our schematics had OScope images of all pins of all logic chips on the board...
10 years later i worked at Microsoft internal IT (software) and first thing they taught us was: Listen very carefully to what the customer (these were MS employees) thinks the problem is and what they think will fix it..after the customer leaves ignore everything they just told you...
My dad is an electrician and he always says, "if someone says the circuit is off, test the circuit. ALWAYS TEST THE CIRCUIT."
Especially when she doesn't bring condoms
Says total novice while the background behind him is full of electronics material, revealing a work of decades. Excellent video by all means, i was very happy to watch it. Definitely this is a material for a seminar in electronics.
@@adriansdigitalbasement you are very good with what you are doing and most important is that you are persistent, you do not give up easily. Too bad that all these bad c64s cannot be fixed by their owners because this is an expensive task as it could take several days even for an experienced electrotechnician.
wow this takes me back, back in the late 80's i used to fix these for a living, a repair company in Monmouth UK called Mills, cant remember having a cool diagnostic cartridge, but i can remember on blank screen faults removing all the top row roms and chips along side of it and using the game Jupiter Lander cartridge game, this game didnt need any of the top row installed and if it worked you knew the fault lay in the chips you had taken out, also piggy backing ram chips, sometimes you could find a duff ram chip by putting a new chip on top of the old one, (just squeezed on top), All this and you didnt need good eyes to work, now I am replacing tiny SMD stuff which i need a mag lamp,
Nice work again mate, took me back 30 years with that video
Personally, I don't see all that many flubs with your repair. It takes a while to develop good practices for troubleshooting and different people use slightly different methods. You're doing just fine.
Agreed, no sure fire 'one best way', all repair guys I have known approach problems from different angles/perspectives.
We all learn from adrians learnings and that’s why we all find this so interesting to watch. We have all been there when troubleshooting.
From someone who has worked in Electronics repair for 20+ years in the private sector and the US Navy, your methods are just fine.
I saw one huge flub. He should have replaced that last botched wire job at 14:22. He fixed all the other wires and left one raggedy yellow wire. I was cringing when he left it on.
CZcams: Do you want to watch this?
Me: ...maybe?
Very thorough diagnostic and repair. And now I forgot what I came to CZcams for, but feel compelled to go get some C64's and fix them! Nice work!
15 years ago when I moved I gave away 2 Vic 20s , 2 64s cassette drive floppy drive monitor all cords software galore and even a printer to a friend who passed since then. I had packed all of it up in the 80s with foam, desiccant, and glad wrap in heavy boxes and stored it in closets for all those years. He said everything was working except the printer no ribbon or ink available and most of the cassettes and floppy’s had magnetic degradation. When he passed awayI hope his new wife found that stuff a good home and not the dumpster. This video brought back memories.
Oh that's great -- so much of it was thrown away. So a good home is a good thing.
Adrian's Digital Basement I wish I still had it now that my life long friend has passed away we used to be one of the first kids to ever have what they call gamer parties or something like that. When we were kids we would bring the whole setups to each others houses next door and program for days. Then we got dial up modems and typed messages back and forth. This was before internet.
I did not realize that "Total Novice" equaled Jedi Master electrical/digital Tech!!! Amazing sir! I have worked in computer software & hardware for 30 years. I found this very relaxing & appreciated your troubleshooting skills! Awesome job in your electrical trouble shooting!! Big LIKE & new Subscriber!
I grew up fixing video games for arcades as a business in the early 80's. All professional arcade machines were designed and built like this. I developed the exact same skills you used to fix this on my own so you are spot on with your troubleshooting and diagnostics approach !
calls himself a complete novice, already has much better test equipment than what I'm dealing with... damn
I feel this in my soul
I got a free multimeter from Harbor Freight and barely enough smarts to follow a diagram to wire an arduino to a breadboard, so this guy is lightyears ahead
41mins of pure joy of fault diagnosis.
41 minutes just fly when you are watching something fun. Besides that why not make a tutorial for testing different components using different tools (multi meter. oscilloscope, probe etc...) I prefer it coming from a non technical person as my self then from an electronics engineer. Thanks and happy holidays.
I didn't realize that the video was that long!
*instant realisation* Wait what? That was 41 Minutes?
novice, are joking your the type of guy whose method gets written into tech journals. very good work
I enjoyed watching you struggle your way through the repair, simply because someone had butchered the motherboard. I particularly liked your logical approach, and your perseverance. It all paid off..
There is a saying which I strongly support in electronics, both for design and repair work: "If it works, it ain't stupid." Nice work!
Gotta love working on a board that someone has messed with and pulled up traces. Having a good desoldering iron with the proper tip is essential to prevent trace damage. For most of my vintage boards, I use the Hakko A1002 nozzle with the 0.8mm diameter. And it's also important to maintain the pump and seals so you get enough vacuum.
The best scenarios are when you know who caused the problem(s), and after fixing the problems, you can explain them all to the person, so they realize their incompetence.
I bought a damage Commodore 64 7 years ago and I fixied with my son, now he is a computer engineer.
tgis video bring back memories.
Best Regards.
When I first trained as an Air Force electronics maintenance technician in 1984, we were still troubleshooting problems down to the component level, like we see in this video. Within a decade we troubleshot down to the circuit card only, and we did not repair them; we went the card to supply and in time we received a replacement. Back when the C64 was a new machine, this much time to repair a defective unit was not economical; it was cheaper to simply throw it out and buy a new one.
"piece of crap socket" - **looks nervously at the sockets I've installed in my PET**
heres a pat on the back it'll be fine my brother it'll be fine don't worry
AUGAT brand sockets my man!!! They are the best! Usually $5-$15 each but if you watch eBay you can get some deals.
I just bought a lot of 20 beautiful gold plated brand new in the package AUGAT sockets for $7 shipped! There a special type, and I could flip those bad boys for $15 each but I’ll hold onto them!
I love collecting vintage IC and transistor sockets. There are some really beautiful examples out there that bring crazy money.
Can't blame yourself if you don't know better!
Can't be that bad in the grand scheme of things, I fix cars and motorcycles as a hobby and the amount of dirt cheap, questionable components that I've used on them with no issues is amazing. If you can convince it to work where it's supposed to the majority of the time it just works, no matter how jankey it is.
Some people say double leaf sockets, but I say machined pin is the way to go. I've used thousands of them, and *never* had a problem with machined pin sockets. Double leaf sockets aren't *terrible*, but I've had a few get crusty and fail. Single leaf sockets are the devil and should never have even been imagined.
jesus just saw it was 41 mins long but felt like 10 mins wow nice work
Wow, what a walk down memory lane !!! I started my electronics career in the early to mid 1990s and my first gig was working for a Commodore Dealer. Since I was good at soldering, the owner made me his #1 troubleshooting tech for C64 and Commodore Amiga computers. It has been so long since I have toyed with any of these computers but your video brought back a lot of memories and your techniques for troubleshooting were great !!! Yes, A diagnostic schematic is a Tech's best friend ALWAYS !!! I would love to watch more videos like this !!! Thank you for the memories !
Pete...
I'm 37 and grew up with a C64C. You make me want to buy another C64. Great video man, I thoroughly enjoyed it.
Thank you Adrian for bringing another C64 back to life. Thanks also for taking the time to make these videos for everyone to enjoy. Merry Christmas to you and may 2020 see more repair and other videos from you.
Steve.
"Look How They Massacred My Boy"
Good job on reviving it.
Good rule to stick to, If you see a bad socket... Just replace it. Clean up all your solder leads and make sure to double check all traces.
* to remove bad sockets, if you can reach the leads, snip them all and then remove the plastic and then remove each snipped piece of snipped legs and clean and resolder the pads.
***But! I want to make certain to say, Great Job! It was a real treat to watch you work on that board and your logic about troubleshooting the issues was very well thought out. Good work and keep it up!
This video was 41 mins long? Geez I didn't think it was nearly that long. Good work dude, that was very entertaining and informative!
My Dad bought his C64 when I was about 4 years old. I'm 40 now. He still has it and it still works. It's never needed serviced or repaired.
These was good times when "programmed wearing" was unknown term. Proper engineering and equipment was made for years (sometimes for decades).
This was like watching a very gripping 41 minute mystery show. Great work!
Desoldering can be a real pleasure with the right tools. I worked with a guy who was a total expert at it. He swore by braid, and modestly quipped that he learned to desolder from the need to undo lots of his own work.
If it is true that you have no experience in electronic and you can demonstrate this level of intuition and intelligence you definitely have a gift. I have seen electronic engineers not able to come close to that level of expertise.
I really like your style in progressing with the diagnostics and I'm glad there's still good care for those hardware gems!
Great video! I usually watch random electronics repair videos late at night so I can fall asleep but I had to pause yours and find another one to watch last night because it was so interesting :) I watched it today and subscribed.
I loved how in-depth you went for all the little details, and the throughout process of trying everything out. Excellent!
I don't know anything about hardware repair and I only ever played a C64 once in my life, not really connecting with it, since I had my Sega MD 2 already...and yet, I can't stop watching. I guess I just love watching people who know their craft do what's magic to me :) And also, I admire people who resort to fixing things instead of just buying new things. It's not like I'm a "no waste" person, but there's a happy middle-ground where you at least TRY to fix, e.g., the ripped pocket on your jacket, instead of throwing it out.
You may go around things differently, but you're my favorite CZcams channel. Folks like you, LGR and the 8 Bit Guy are the best. Merry Christmas and Happy New Year to you.
My gosh you were determined to get that fixed. I think my patience would have given out quite awhile in to the project and I would have declared it a parts machine. Good job!
Good video. I run an R&D lab where we build electromechanical test equipment. I mentor Electrical Interns often and also have technicians who work for me. One thing I train my people to do when they are troubleshooting a problematic circuit board is to use a known good board, save the scope image of the different signals for the data lines you need to troubleshoot to a library on your PC. This way when you are troubleshooting the bad board you need only to pull the images up for the pins to see what the data lines SHOULD look like to know if what you suspect is bad is correct. This has saved me a lot of time over the years.
Great work Adrian. I have run into lots of issues with C64's over the years. It is great to see somebody working on them, troubleshooting them and giving useful tips. This information will be no doubt useful to somebody either now or in the future.
The 113 thumbs down were the previous owners of that CPU board 😂😂😂
It is interesting to see that the test harness, whilst very useful, can only go so far. Then you are back to reading the schematics.
Thank you for reminding me of the important lesson of looking at the board first for 1) Broken traces 2) Bad/broken/dry solder joints. It is just so easy to jump in and start de-soldering components.
@@adriansdigitalbasement but it wouldn't have given us a full 41 minutes long good entertaining!
Nice work! I remember I used to use a rubber ball suction tool to remove solder and it took hours to make sure I had completely cleaned a connection. Another trick I used was a steel wire that I wound around my soldering pen to make a very tiny tip to clean out socket holes. My son and I used to play games on his Commodore 64 and had a lot of fun together. The main problem I used to encounter was flimsy connections that I had to resolder. My son now works in IT but still remembers the fun he had in simpler times.
This was the most awesome repair video I have ever watched. You are amazing having not given up. I'm sure you felt good after seeing that running again. Thanks for sharing.
Your videos are always an education.
Yes, I think so. :3
I have never cared for Commodores, growing up at the tail end of that era, but this video was very interesting! Good job getting it working right.
HOLY CRAP MAN! I loved (LOVE) my old Commodore 64 that has been dead for over 25 years. The sound doesn't work and the 1541 drive doesn't read, but I do get the blue ready screen. I have never seen any tutorial like this and I was fired up after seeing you do this! Your skills are off the hook and you make this look SO easy! I know its not and would never attempt this type of repair at my level (or lack thereof) but this was absolutely fascinating to watch! Thank you!!!
I very much enjoyed watching your troubleshooting process. Things are complicated when there are compound problems and a lot of people would quit in frustration rather than break it down into ever smaller problems to fix. Great work!
I can't believe I watched the entire video. I found it fascinating and really informative. Great job!
@23:42 "So to recap..."
Me: "Oh, you're going to replace all the capacitors next???"
a lot of leaking capacitors there...
I just spent 40+ minutes watching Adrian fix a 64 and I loved every minute of it. What a great video. Thank you!
I've repaired thousands of C64 motherboards in 80's and that was just painful to watch. Lol. Glad you finally got it working.
I was out of ideas before you were 5 minutes in.
Time for a backup solder station. I deal with removing IC’s and have used your hot air method. Lifted/ripped traces will test patience. Enjoyed this video as it covered several Troubleshooting techniques.
What a great video. Its good to see people taking an active part in making sure these computers still survive and work. Merry Christmas!
Adrian, thank you for taking us on this journey. Your diagnosis methods are just fine. As I’m sure you know, there is seldom a mapped out troubleshooting guide that will cover all potential faults especially when stacked up like this board. One of the most expensive aspects for NASA and Military projects is the need to reduce fault isolation as much as possible even if there’s only a once in a million chances the fault condition will occur. Working on commercial products is all learning the obvious weaknesses, and a strong sense of intuition. I see nothing wrong with your methods. Teaching them to others especially while showing all the ugliness builds that intuition. Thanks again!
"This socket is a piece of crap!" - Yeah.. as soon as you pulled that chip, I said the same thing in my head.. I hate those sockets too!
they cause more issues than they fix, I've had to remove many from all sorts of equipment a bad one is 8 pin op-amps in amplifier early stages, had them go intermittent and drive output stages to near full DC rail voltage and cook speaker coils!
@@throttlebottle5906 Interesting! I hadn't considered a scenario where a failure like that could cascade to another failure but that's a good thing to remember! I generally run into them on old vintage arcade machines (PacMan and Williams pinball machine boards, specifically..) where it may cause something not to work, but I've never seen it break something else!!!
I own a Donkey Kong arcade machine and have had issues with IC sockets as well
I ended up watching for the whole length waiting with baited breath each time you switched the power on.
That pictorial fault guide page is very handy. I had a fault that I got published on there, the broken trace fault at the bottom of the page. Nice work on fixing this machine! It is so satisfying to finally get to the bottom of a problem and get the beautiful blue screen of life on a C64.
This is the best C64 repair video I've ever seen. While so many just seem to document a PLA swap, here I think you hit (and remedied) the majority of issues I've found with C64 motherboards in one go.
This was easily the best video you have ever made 10/10
It was pretty common for the RAM chips to fail. I remember doing lots of those back when I worked for a school board that had hundreds of C-64s
Great video. Poor C64 was abused by other people that don't know to do proper repairs. Its great to see you bring it back to life.
Great repair Adrian. Another C64 back in operation. Though this is one of your longer videos, it didn't feel like it, it flew by. I'm also enjoying your improved audio and video, nice job 👍
Enjoyed this immensely. I would attribute your aversion to novice status to the Dunning-Kruger effect. Bookmarked The Pictorial C64 Fault Guide. Hopefully it will help with my C64 character ROM issue.
Don't you mean the imposter syndrome? This is a case of a person who clearly knows what it's doing but is saying otherwise. Still... as any expert on any field keeps learning new stuff, they become more and more aware of all those things that they ignore. Therefore you have Socrates there saying 'I only know that I know nothing'.
Leandro Tami Dunning-Kruger effect is about both novices overestimating their ability AND more knowledgeable people underestimating theirs.
I might just be a geek :-D But even though I have spent ages online, watching all kinds of videos, this video is one of the most interesting and satisfying videos, I have seen
That was my impression also. It was good to see an actual diagnostic video test, rather than someone who just knows and thinks the viewer knows so they omit anything that actually helps us newbs understand these things. Nice vid Adrian!
Impressive! A lot of comments have already mentioned the "novice" thing, but I would probably describe you as a magician when it comes to this stuff. My knowledge completely ends with knowing it requires electricity to run.
Just a few comments. I owned a PC shop in Charlotte NC in the 80's and did component level work on MANY types of computers and peripherals. I suspect I and my employees, repaired more than 500 Commodore boxes, mostly C64's but also some VIc 20's, C128's and others. The C64 was a great unit and provided a lot of bang for the buck back then.
A business associate turned me on to the AIRVAC handheld desoldering tool and the day we got the first one was a fantastic day. The tool required a shop compressor which turned ~90psi to ~20" of vac at the tip.
For removing IC's and sockets it was so good, often just turning the board upside down, the IC would fall off. We took time each day to clean out the solder trap and it would work very well for the day. I still have several of them in my lab. Once the trap starts getting about half full, the performance drops quickly.
I also have a Hakko which is better for larger ground planes but for IC's, transistors the AirVac is outstanding..
They are still sold, not cheap but it will pay for itself quickly.
You should remove the shorted zener diode since it will be pulling current and heating up.
Here is the link for the AirVac tool I use. Oh, keep an eye on ebay for used units at a lower price.
www.air-vac-store.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=AS&Category_Code=PVSG
Regards,
Glenn
DSM Labs
I never liked that cassette high-side switch circuit. When I was a lil un using my C64 with a data-cette, I had at least two repair visits that I remember having to take the computer in to get the transistor replaced. When I went over to disk drives that issue was effectively bypassed. I imagine nowadays that the high side switch is akin to an appendix on a C64.
Seasons greetings, thanks for the content from 2019.
Cheers,
Makes me wonder why they didnt use a PNP transistor instead as a switch. That would have made more sense in that highside switch circuit.
@@ulfen92 - Thats' a good point. I think the NPN was used as the circuit acts also as a linear voltage regulator. The zener on the base ensures that the emitter voltage is clamped at .6v below the zener voltage. This helps to roast the transistor causing it to fail as there is no heatsink on it. -_-
Cheers,
That TO-66 is a pretty husky transistor for the purpose it is used for. My experience was that the cassette drive would get plugged on incorrectly or an aftermarket cable would short the output of the transistor to ground and fry it before the 9V fuse went.
"I'm an electronics novice"- made me spit out my wine 😅🤣
same here
Oh man, I'm finally starting to feel more confident to start approaching circuit troubleshooting using schematics now, especially since now you've shown results of many mistakes caused by previous repair attempts. Going for round-hole sockets is a nice tip too!
you just did a great Job on that C64 Board , I've never saw a Tech doing such a repair like the one you did, congratulations.
TS100 tip: if you've got the XT60 to DC barrel cable that's commonly offered with the TS100, that cord is a piece of junk. The wires in the cable are awesome, but the strain relief is bad - it makes the wires fray and break with moderate use. Check for continuity in the DC barrel while manipulating the strain relief. You might need to strip the molding off it and resolder, hot-snot the thing back together. Maybe.
Hmm, I also had my TS100 power jack go bad, but it was the wallwart Sainsmart one. I've since replaced it with a JBC Compact iron, but I would still like to fix the old TS100. Perhaps I might try bending the lever in the barrel jack a bit inwards.
This video was amazing! Your tenacity during the troubleshooting process was very impressive. If you are at all interested in attempting to repair a faulty Atari 1040 STf please let me know. I've had the machine for about 1 year and can't get video to display. Big fan of your videos!
Have you picked up the Diagnostic cartridge? I think BEST sells one, which is where i got mine. I ended up having to just pick up another 1040STF and do chip swapping.. once you figure out the chip, you can just resell the 2nd computer on ebay. With my 520ST that couldn't display video, I ended up replacing the C025914-38A chip. You're using the original monitor, I assume?
@@brianv2871 Thank you for the advice. I don't have the diag cart. I always figured the issue would be the Shifter chip or the glue chip. I actually have a working Atari 520 STf but have always been weary to swap the chips as they don't look identical to what I see on the 1040STf and didn't want to risk damaging components from my working system to test the 1040. I don't have the original monitor but do own monochrome and color VGA cables that works with an Acer monitor capable of the 15khz refresh rate. This of course has been tested on the on the 520. Thanks for the advice!
so my two boards, the chips were slightly different as well, but googling i determined the parts were just newer revisions (something like 30 vs 30a). But yeah, i guess do what your comfortable with, but the 520stf and 1040stf were essentially the same machine but with more ram. in fact, my 520stfm had empty slots that could be filled to make it a 1040. I never bothered with that since i used to have a ram module that stopped working and might just get or make another one at some point. I only asked about the monitor because I've not had luck using the special cables (like composite, or the scart cables) on non modulated ataris, but i assume if your setup works on a non modulated Atari then you're good there. Anyway, don't think Adrian could really help on this, because even if he could diagnose the issue, he'd need parts to swap in, and he doesn't really have spare parts for them like he does commodore. If i recall, he just has the STE, which has different chips.
@@abar1120 no video output is not necessarily a video fault - my STe had no video output and it turned out it was the reset circuit that was at fault -bad output on the 555 timer chip was causing the reset line not to be toggled correctly on power up
@@brianv2871 chip swapping is just guessing
Excellent repair and troubleshooting. Thanks for taking the time to share the journey!
Unbelievable that C64 is still so much around among people. And then even putting so much time and effort in, wauw. Eventhough I see you using ESD safe mats for your cmos-chips, I don't see you wearing any ESD-wriststrap while you do wear polyester-based clothing?! Or maybe the strap is on your ankle :-) So recognisable the ups and downs during repairs. I've worked for 9 years in a repair centre, going through this each day. Fun part of this 80's tech is that it is still perfectly understandable and repairable, in contrairy with modern SMD-components and the impossibility to obtain circuit diagrams. Thanks for sharing this experience on YT
Thank you for saving my childhood. Imagine if these were ROHS, then there would be no way of getting these to be alive again. I stopped putting my failures in videos because I feel CZcams saw them as demonetization issues. Mind you they never tell you why your video is demonetized. Funny how some people don't say the 'L' in soldered. Maybe I'm saying it wrong.
We Americans tend to drop the l in soldering.
34:57 "Bring in the Logic Probe!" - Sark / TRON
Very complex array of problems. Incredible how you didn't give up and went step by step fixing it. Taught me a lesson.
You give yourself way to little credit and I have repaired similar Atari Products in the 80's myself. Nothing wrong with your troubleshooting skills and you are NO novice. Well Done- that was great to see it all come alive. Best for the future.
Oh dear, this poor Commodore sure has seen better days, it's always satisfying to see a machine fire up and just work after you spend countless hours tackling its problems.
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Aye, while it's not as impressive, I too, got my hands dirty and started tackling a project: my friend's Amstrad CPC 6128, it won't read any disk, and the floppy drive makes weird noises... And it has a intermittent fault where the keyboard intermittently stops responding.
For now, I've dismantled the drive and found out that the belt is gone (it has melted away, and trust me, cleaning melted rubber is a pain, thankfully I had rubbing alcohol on hand, it more or less worked fine), for now I haven't put it back and will need to order a new belt. After that I'll move onto the keyboard issue...
Yikes! It sounds like you definitely have a lot of work ahead of you! It's great though that people are fixing vintage computers and bringing them back to life. In a way, it definitely is helping to preserve a part of history.
@@ct92404 yeha in a way, it feels like restoring preserving a ancient artifact from the past, so it doesn't fade into the abyss of the forgotten things.
That aside, this Amstrad is quite a simple machine, it's just yet another Zilog Z80-based computer, nothing too far-fetched, they were built to be cheap (from what I heard about them), but surprisingly the one I'm restoring has held up pretty well (save for the drive belt melting and the keyboard ribbon connector being flaky), though on the outside it's near mint, save for a few blemishes, but hey, it adds a bit of character to the machine, right?
I think someone had that character ROM issue when they invented the Ancient script for Stargate.
The machined sockets are much better than those that were used on that poor C64. Anyway, great troubleshooting!
Wow! What a monumental effort to fix that board!! Awesome that you completed it! Congrats!!
Fixed. Now give the customer the bill for around $2k of time... and BTW, no warranty... thank goodness I'm not in to heritage electronics repairs... anymore...
I was an Atari guy back in the day... why am I watching 41 minutes of a guy repairing a C64? at 1am?
Me too, my first serious overhaul was expanding RAM in my Atari XE to 256kB for Sparta DOS RAM-Disk. Works lika a charm for few years until PC come on my desk.
I don't recall doing any hacking on my 800, but I did hack and ultimately killed my 520ST. First I separated the keyboard from the rest of the computer, because I hated having all the cables stretched across my desk to where I wanted to have the keyboard. Initially I just had the keyboard in the empty case connected by a small cable to the mainboard at the back of the desk under the monitor stand; I planned to cut the case down to a more proper keyboard size, and then put the mainboard back into what was left... Never got to it though before I killed it doing a memory upgrade with some bad solder from radio shack. Then I got a Mega ST2...
Ah this take me back to my 386/486 chipset days
I am a C64 fan. I know nothing about electronics, but I saw all your 41 mins video and found it very interesting. Thanks!.
You've got the best skills to do effective troubleshooting. Sheer tenacity and mental focus. Also, like a Dr you do no harm. The fact that you diagnosed & repaired it down to the component level of even components you don't know proves that. And this comes from some one who was trained in one of the best electronic colleges in the country. Most troubleshooting comes down to two methods. Divide & conquer. Or signal tracing. The largest percentage of repairs are mostly PSUs and what you did was much more complex.
I enjoyed watching you diagnose this computer. I am also a novice at Electronics. I would say you are about a year ahead of me or so. I have learned quite a bit by watching you. I've noticed that the schematics are starting to look a lot easier to me. (they make a lot more sense). I would imagine as with any new language, it all seems overwhelming at first, but after a while things just start falling into place! :-)
Wow - that's what I call a labour of love! How many hours went in to that repair?
@@adriansdigitalbasement
that's true
filming it and having to explain shit all the time , really slows down the process.
i reckon you probably took an hour or two realistically if you didn't have to video or explain stuff
me and a friend recently repaired a COMMODORE P.E.T.
initially had display but it was all Garble
at the end of the day ....... Character ROM and buffer had to be replaced
all fixed now
in total... Probably around 1.5 to 2 hours and maybe 5 cups of coffee LOL
but.. it was fun
Your patience and perseverance are becoming legendary . Love watching your vids
Your shout-out to IZ8DWF at the end was great👍.