Excellent job =D Came out really well - that display was very bad until you cleaned inside and out the front panel! Sorry I've not had chance to even open that box yet - Had so much stuff to get out of the way (mostly for other people). Should get some time soon, looking forward to it =D Thanks for the very kind words too =D
I believe the reason the fan was running full speed was due to the missing communication between the analog board and digital board. The HP/Agilent source measurement units will do the same thing if a fault is detected on the current source board.
@10:15 I would just push the plastic retainer back in and then apply some tape to hold it in place, it just needs to be there to push the flex onto the terminals inside the connector.
Great quick repair! 👍 Interesting, what may be reason for this ribbon cable socket to break.. My versions are: some previous maintenance goes wrong or previous transportation, because never seen, that these connector's broke by it self..
I doubt it broke by itself.....more than likely the folks at the company that owned wanted to upgrade their test gear and opened it up an hauled at the ribbon to create a fault......happens more than you think!
Hi Thanks for the info. Did you ever get a schematic? I have a problem on the control board. would there be a way to get a copy if you have one? Best regards
@@IanScottJohnston I knew that, but I don't hear it called IPA very often... We call it ISO or just alcohol... Nicely done on the refurb... Want a real challenge? I have a 1990s Tesla BM 595 RCLG meter... You might have better luck finding documentation than me... It's a beautiful unit... Probably just needs new Caps...
Nice repairjob. I am maybe a bit pickie, but for a precission instrument, the output voltage (even at low loads) isn't as precisse as I would hope it should be. Is that really OK this way, or is there a hidden failure?
Thats a fair question. So, remembering it's a System Power Supply and not really meant as a general bench unit, the accuracy comes when using the rear phoenix terminals and the sense terminals there. I tested them and even with a 5A load @5Vdc the output only dropped by about 0.5mV. The user manual states: _"Front binding posts are provided for convenience. Only the rear panel terminals are optimized for noise, regulation, and transient response as documented in Appendix A2"._ Without opening it up again, I can only assume the 'local' mode sense connections don't go all the way to the back of the front binding posts, and probably the gauge of the wire there is questionable also.......and thus volt drop is experienced even with minimal loads. If I was keeping the PSU I'd probably modify it for that.....an easy mod to make......:-)
Thats a lot of power supply just for 8V 5A. I wonder if there is a way to modify it to allow a higher maximum voltage even if just up to 12V. What is the main output voltage from the transformer? 8V 5A is not very useful.
It's very useful if you need a PSU specifically for supplying a low-noise voltage in that range at substantial current. This is a system supply, not a general purpose bench supply.
@@IanScottJohnston I'm not sure I liked the idea but was willing to be sold on it. Looks a right faff to get the meter out of mine otherwise I'd give the cover a serious polish, it's quite scratched as it seems to have seen serviced in a college. Perfectly readable but could be prettier.
Ian could you make your videos shorter? 10-15 min. is ideal they say... Instead of discussing the issues with the viewers you could just expose/share the faults and your conlusions w/ us, we would save time. Nobody doubts your integrity I reckon.
10 to 15 mins is what they say "in general", but technical content i believe requires more time to properly explain or show stuff without having to go at 100mph. In the Agilent power supply repairs folks questioned why I didn't show the actual calibration procedure....so this time I did.
@@IanScottJohnston Ok. The calibration is explained in every user manual but ok... if you audience wants that. For me often the length is a dissuasive factor. For example in this one I jumped from section to section to finish the video.
No particular length is best for every viewer nor every type of video. Some people want more detail, others want less. At least with longer videos, you have the option to skip past things that aren't of interest. Videos can also be played at higher speed to save time. I often use 1.5x speed.
Excellent job =D Came out really well - that display was very bad until you cleaned inside and out the front panel! Sorry I've not had chance to even open that box yet - Had so much stuff to get out of the way (mostly for other people). Should get some time soon, looking forward to it =D Thanks for the very kind words too =D
It's always a pleasure to watch. Thank you.
Enjoying all the power supply goodness, Ian. 👍
You are one lucky man.
I love the way these heat-sink/fan combo are made. Practically dust proof.
Love your videos at all. Thanks. 👍
Excellent repair! Thank you.
I believe the reason the fan was running full speed was due to the missing communication between the analog board and digital board. The HP/Agilent source measurement units will do the same thing if a fault is detected on the current source board.
Excelente vídeo
New Brymen 786 nice post as always
Yes, I liked the 121GW, but it wasn't easy for folks to read the LCD on video.
@10:15 I would just push the plastic retainer back in and then apply some tape to hold it in place, it just needs to be there to push the flex onto the terminals inside the connector.
I'm selling the PSU afterwards so tape isn't an option. Borrowing the clip from the unused port seems the best way.
Yes, get some plaster ... (scnr) ✌️
Great video,keep it up!*
Nice !...cheers.
Nice repair :) Love HP kit, normally rock solid. For that connector to be damaged someone has fat fingered it, Question is, why were they in there?
Great quick repair! 👍
Interesting, what may be reason for this ribbon cable socket to break.. My versions are: some previous maintenance goes wrong or previous transportation, because never seen, that these connector's broke by it self..
I doubt it broke by itself.....more than likely the folks at the company that owned wanted to upgrade their test gear and opened it up an hauled at the ribbon to create a fault......happens more than you think!
Ty and nice this is easy method
Hi Thanks for the info. Did you ever get a schematic? I have a problem on the control board. would there be a way to get a copy if you have one? Best regards
IPA? India Pale Ale to clean the contacts...
It's better than using a single malt I guess...
Dang!.....my secret is out!
IPA alcohol actually.
@@IanScottJohnston I knew that, but I don't hear it called IPA very often...
We call it ISO or just alcohol...
Nicely done on the refurb...
Want a real challenge? I have a 1990s Tesla BM 595 RCLG meter... You might have better luck finding documentation than me... It's a beautiful unit... Probably just needs new Caps...
Nice repairjob.
I am maybe a bit pickie, but for a precission instrument, the output voltage (even at low loads) isn't as precisse as I would hope it should be. Is that really OK this way, or is there a hidden failure?
Thats a fair question. So, remembering it's a System Power Supply and not really meant as a general bench unit, the accuracy comes when using the rear phoenix terminals and the sense terminals there. I tested them and even with a 5A load @5Vdc the output only dropped by about 0.5mV. The user manual states:
_"Front binding posts are provided for convenience. Only the rear panel terminals are optimized for noise, regulation, and transient response as documented in Appendix A2"._
Without opening it up again, I can only assume the 'local' mode sense connections don't go all the way to the back of the front binding posts, and probably the gauge of the wire there is questionable also.......and thus volt drop is experienced even with minimal loads. If I was keeping the PSU I'd probably modify it for that.....an easy mod to make......:-)
Thats a lot of power supply just for 8V 5A. I wonder if there is a way to modify it to allow a higher maximum voltage even if just up to 12V. What is the main output voltage from the transformer? 8V 5A is not very useful.
It's very useful if you need a PSU specifically for supplying a low-noise voltage in that range at substantial current. This is a system supply, not a general purpose bench supply.
Easy fix this time. :-))
Were you going to/did you swap out the meter for digital on your Farnell supply? Was interested to see what you decided on.
I reverted it back to the analogue meters.....too many folks didn't like the idea....:)
@@IanScottJohnston I'm not sure I liked the idea but was willing to be sold on it. Looks a right faff to get the meter out of mine otherwise I'd give the cover a serious polish, it's quite scratched as it seems to have seen serviced in a college. Perfectly readable but could be prettier.
Ian could you make your videos shorter? 10-15 min. is ideal they say... Instead of discussing the issues with the viewers you could just expose/share the faults and your conlusions w/ us, we would save time. Nobody doubts your integrity I reckon.
10 to 15 mins is what they say "in general", but technical content i believe requires more time to properly explain or show stuff without having to go at 100mph.
In the Agilent power supply repairs folks questioned why I didn't show the actual calibration procedure....so this time I did.
Мне больше нравится смотреть длинные видео
@@IanScottJohnston Ok. The calibration is explained in every user manual but ok... if you audience wants that. For me often the length is a dissuasive factor. For example in this one I jumped from section to section to finish the video.
@@myelectronicsworld don't get me wrong though......your input as is everyone else's is much appreciated and taken on board. Cheers.
No particular length is best for every viewer nor every type of video. Some people want more detail, others want less. At least with longer videos, you have the option to skip past things that aren't of interest. Videos can also be played at higher speed to save time. I often use 1.5x speed.