Ian, brilliant work, and a very nice instrument at the end of all your effort. You would not bore us with the calibration run through!! Would be very interesting to see how the accuracy fares given the number of issues, donor board etc. Thank you for sharing your work.
Best repair I've ever seen, totally epic and really interesting. Thanks for sharing this... and yes, I echo the other comments in saying the calibration video would be awesome...lets see this one through from soup to nuts....
Ian, brilliant series of this fix, I’ve only just found your channel, and wow, you went all out on the repairs, keep up the great work mate, your friend from Australia… 🤙🏼🇦🇺
Discovered your channel after seeing your chat with Dave on The Amp Hour podcast. Love this series! What an epic repair! I'm really surprised at how poorly designed that 110/220V selection feature is on the preregulator circuit. For a meter this expensive you'd think they would include a bare minimum of protection circuitry to cut power in the case that the relay fails and puts 220V on the 110V primary winding. So many ICs could have been saved from untimely death!
Yep, excellent showcase on 2001 repair project. Not all of them actually as this bad to fix, but many are, thanks to old leaking Nichicon VX caps placed next to very hot linear regulators. Calibration is bit messy with 2001, since you do need perform both user and factory calibrations and need provide FS on each range and some high voltage AC calibration signals. Unlike other meters, 2001 wants all steps performed in specific order and will not save calibration data unless all steps are completed without any errors.
Update: Finally got around to doing a full test and yes, loads of errors, mainly 4xx errors, which I traced to a broken DATA connection to U530 which was stopping the dual DAC from working. I now only have one error, 412.1 ACA Switch which I haven't traced down yet. Some folks are mentioning CR305......I'll have a look.
well done! what a great repair series and exellent fault finding reasoned approach all along the way. very glad to see after TSP's video which made this thing look a lot more daunting. it has added to the the body of expertise in fixing these keithleys. much appreciated
Hello, absolutely first-class demonstration of the repair of such a complex device, I watched the whole series, I played some passages several times. I am always very happy when the repair is successful and congratulations on getting a new multimeter. Unfortunately, I cannot fulfill your request to send the defective equipment for repair, I have collected quite a lot in my life, but my workshop was stolen and I lost everything. I start from the beginning and this is not a cheap affair in the Czech Republic. I wish you a lot of success and look forward to more interesting videos, I don't know about the others, but I am improving in the field of electronics in this way. T.H. Edisson wishes everyone a beautiful day
OMG!....very sorry to hear you lost everything. I have had cars stolen, but never my test gear. I wish you the best of luck in building your gear back up again.
@@IanScottJohnston It was a wild week, he started stealing tools and measuring equipment from the car and ended up in an empty workshop 🤪 You have an interesting power supply (the blue one) 👍
This episode takes me back to memory lane. I don't miss those 2001 :) Sounds like fan need replacement. You left us hanging with no self-test result. That's when real repair starts ;-).
Outstanding work, Ian! It is always interesting to see the thought process of others when troubleshooting and repairing a piece of gear. As others have said, I would like to see the calibration process especially in light of Xdev's comment on the complexity of calibrating this model! Regards, David.
Hello Ian. It looks good now. I would suggest to let it stay on for about week(so it get baked to correct temperature for some time and to remove some humidity from board..that will take some time) and after that start re-calibration. It does looks good. I wasn't able to do full calibration(too many things..)..but i was able do that calibration with two voltage sources and two resistors..That should be easy to do for you as well. Nice video.
I'll be calibrating some PDVS2mini's is a few weeks, so the 3458A will be summoned into action then......perfect timing for soak test and then cal against the 3458A.
@@IanScottJohnston aaa I envy you..I want to calibrate my 732A(to get some exact number) and also my 343A .. but too bad ..it will take some time ..till i would be able get them into some lab..it just cost too much to calibrate any of those .. Nice i wish it will go perfect..but i'm a bit disappointed in 2001 performance in that stability and noise...but i hope it will improve with new item on my watch list ..better not say wit what :) haha
Great repair, you succeeded the impossible. Btw. did you notice the read DC value from voltage source was *changing* while you varied the AC supply. Like something is still not regulated or exactly right
So how do you calibrate this so that you have 6.5 digit accuracy? The needed calibrator costs more than a used working meter. Awesome repair in any case.
I abandoned the side swipe DIP sockets a long time ago, except if they were on board already when I received the item. Then I just pulled and re-plugged the chip. But when designing the board or installing sockets myself, I changed to the 4-side contact types. Much more expensive, but never any problem. Well, not quite true, once I had to troubleshoot a solder bridge under the socket. That solder job was not mine, though. The fact is the fatter metal on the underside can increase the chance of excessive solder forming a bridge despite of board solder mask.
Love the videos. I always learn something new to add to my knowledge base. Regarding the AC power supply, seems to me that circuit was designed to take out the entire board! I certainly hope Keithley is better than that, but I now have my doubts about their ethics.
Wow, that was a great repair job. And now we know the secrets how these meter can fail. Quite catastrophic how the pre-regulator/voltage selector circuit can end up destroying every chip on the board.
Great efforts Ian….thorough as always in working through all those faults. Can you tell me what was the part number for the power mosfet in the the pre-regulator….?
Excellent repair journey, thanks for sharing! Looking forward to seeing the calibration vid. One question: why did the (uncalibrated) reading vary so much when you slowly changed the line voltage? Is the 230V line voltage directly controlling the unregulated +/-8V supply?
2 reasons I removed that function: 1. To stop future self destruct. 2. Not easy to isolate the circuit in order to repair and test, even if I could have done it how reliable are the relays etc.
Epic repair, not many would try with such so much damage with a massive voltage overload which takes out fixed regulators, well done. Any idea what the root cause of the over-voltage was? i.e what failed in the voltage selection circuit or theories?
I new those 4 DVM bench meters would come in handy - You enjoyed the repair wow you enjoy punishment LOL. I know I guy that has two Solarton 7075s that dont work?
My fluke DMM's only ever get used when I am doing this sort of multi-voltage monitoring. Very handy! I know a guy also that's got a couple of 7075s that he'll be working on soon.
Ian, brilliant work, and a very nice instrument at the end of all your effort. You would not bore us with the calibration run through!! Would be very interesting to see how the accuracy fares given the number of issues, donor board etc. Thank you for sharing your work.
I wish one day I would be as careful, thorough, and patient as you Ian!
Best repair I've ever seen, totally epic and really interesting. Thanks for sharing this... and yes, I echo the other comments in saying the calibration video would be awesome...lets see this one through from soup to nuts....
I really enjoyed this masterclass video series. Thanks fot putting in the effort
Great series. I enjoiyed it as much you did I think. Please complete the series with the calibration.
Ian, brilliant series of this fix, I’ve only just found your channel, and wow, you went all out on the repairs, keep up the great work mate, your friend from Australia… 🤙🏼🇦🇺
Welcome!
Discovered your channel after seeing your chat with Dave on The Amp Hour podcast. Love this series! What an epic repair! I'm really surprised at how poorly designed that 110/220V selection feature is on the preregulator circuit. For a meter this expensive you'd think they would include a bare minimum of protection circuitry to cut power in the case that the relay fails and puts 220V on the 110V primary winding. So many ICs could have been saved from untimely death!
Yes, it was an epic repair!......loved it coming together and that power up when the pre-reg did it's thing. Agreed it is an oddball design!
I knew you would get there, congrats on a job well done, look forward to the calibration video
Nice job Ian. Enjoyed the series.
Ian, very well done! Like to see how you test and calibrate this unit.
Yep, excellent showcase on 2001 repair project. Not all of them actually as this bad to fix, but many are, thanks to old leaking Nichicon VX caps placed next to very hot linear regulators. Calibration is bit messy with 2001, since you do need perform both user and factory calibrations and need provide FS on each range and some high voltage AC calibration signals. Unlike other meters, 2001 wants all steps performed in specific order and will not save calibration data unless all steps are completed without any errors.
Haven't look yet, but I was wondering whether re-cal via GPIB allowed for individual cal and not "the whole lot".
Update: Finally got around to doing a full test and yes, loads of errors, mainly 4xx errors, which I traced to a broken DATA connection to U530 which was stopping the dual DAC from working. I now only have one error, 412.1 ACA Switch which I haven't traced down yet. Some folks are mentioning CR305......I'll have a look.
Awesome series and end result Ian, especially as I was able to binge watch all of it in the one sitting!
Thanks for all the work getting this up & running , and thanks to whoever donated the other unit ;)
Absolutely brilliant job Ian. I too love the series of videos to 1 repair. Thanks for sharing.
well done! what a great repair series and exellent fault finding reasoned approach all along the way. very glad to see after TSP's video which made this thing look a lot more daunting. it has added to the the body of expertise in fixing these keithleys. much appreciated
Very kind words.....thankyou.
That was some heavy duty repair, congrats!!!
Excellent job Ian, I have enjoyed watching all parts. I would also like to see a video on the calibration, as several others have requested, please.
Hello, absolutely first-class demonstration of the repair of such a complex device, I watched the whole series, I played some passages several times.
I am always very happy when the repair is successful and congratulations on getting a new multimeter.
Unfortunately, I cannot fulfill your request to send the defective equipment for repair, I have collected quite a lot in my life, but my workshop was stolen and I lost everything. I start from the beginning and this is not a cheap affair in the Czech Republic.
I wish you a lot of success and look forward to more interesting videos, I don't know about the others, but I am improving in the field of electronics in this way.
T.H. Edisson wishes everyone a beautiful day
OMG!....very sorry to hear you lost everything. I have had cars stolen, but never my test gear. I wish you the best of luck in building your gear back up again.
@@IanScottJohnston It was a wild week, he started stealing tools and measuring equipment from the car and ended up in an empty workshop 🤪
You have an interesting power supply (the blue one) 👍
Smashing stuff ! Dont think the calibration would be boring but what a result !...cheers.
This episode takes me back to memory lane. I don't miss those 2001 :) Sounds like fan need replacement. You left us hanging with no self-test result. That's when real repair starts ;-).
When I have all the gear for a proper re-cal I'll do a video. The self-test results.....errrm, yeah!......another video maybe!
Put a note on the board to say why parts are missing. Love the videos thanks for sharing
Great result. You must be a happy man.
great to see the readings are not too far off even with no cal.
Outstanding work, Ian! It is always interesting to see the thought process of others when troubleshooting and repairing a piece of gear. As others have said, I would like to see the calibration process especially in light of Xdev's comment on the complexity of calibrating this model! Regards, David.
Wow, what a journey! Top work there diagnosing all those faults!
I would love to see the calibration process. Thanks for these videos, they are great.
What a repair!!! Thank you.
Well done sir! That was a fun ride!
A brilliant series!!! I very much enjoyed and looked forward to each part =D And a fantastic end result for all of the hard work!
For someone without any of these high end equipments, seeing what the calibration process is, even abbreviated, would be very interesting to me.
Well done Ian, brilliant work. Well worth the toil.
cool repair vid,thumbs up!
Hello Ian. It looks good now. I would suggest to let it stay on for about week(so it get baked to correct temperature for some time and to remove some humidity from board..that will take some time) and after that start re-calibration. It does looks good. I wasn't able to do full calibration(too many things..)..but i was able do that calibration with two voltage sources and two resistors..That should be easy to do for you as well. Nice video.
I'll be calibrating some PDVS2mini's is a few weeks, so the 3458A will be summoned into action then......perfect timing for soak test and then cal against the 3458A.
@@IanScottJohnston aaa I envy you..I want to calibrate my 732A(to get some exact number) and also my 343A .. but too bad ..it will take some time ..till i would be able get them into some lab..it just cost too much to calibrate any of those ..
Nice i wish it will go perfect..but i'm a bit disappointed in 2001 performance in that stability and noise...but i hope it will improve with new item on my watch list ..better not say wit what :) haha
@@IanScottJohnston You'd also need 3245 for low frequency AC ;-). Coming right up...
Whoop whoop!
Great repair, you succeeded the impossible.
Btw. did you notice the read DC value from voltage source was *changing* while you varied the AC supply. Like something is still not regulated or exactly right
I'll take a look, cheers.
A great series Ian, very much enjoyed it. Thank you! I hope you'll get your wish for more Titanic repair projects requiring Herculean efforts ;-)
Great job Ian. This was an awesome series to follow 👍
Hi Ian, I wonder how many Keithley Technicians watched your video. Maybe you will get a new flash unit in the post 😁
Cheers Dave.
Would really like to see the calibration and self test process! 😀
You did it, realy great and top work.
at last the wait is over a great series for this repair, shame the original was so knackered though 🙂
Excellent repair 🤓👍
So how do you calibrate this so that you have 6.5 digit accuracy? The needed calibrator costs more than a used working meter. Awesome repair in any case.
I abandoned the side swipe DIP sockets a long time ago, except if they were on board already when I received the item. Then I just pulled and re-plugged the chip. But when designing the board or installing sockets myself, I changed to the 4-side contact types. Much more expensive, but never any problem. Well, not quite true, once I had to troubleshoot a solder bridge under the socket. That solder job was not mine, though. The fact is the fatter metal on the underside can increase the chance of excessive solder forming a bridge despite of board solder mask.
Love the videos. I always learn something new to add to my knowledge base. Regarding the AC power supply, seems to me that circuit was designed to take out the entire board! I certainly hope Keithley is better than that, but I now have my doubts about their ethics.
Wow, that was a great repair job. And now we know the secrets how these meter can fail. Quite catastrophic how the pre-regulator/voltage selector circuit can end up destroying every chip on the board.
Do you already have a video out on calibrating one of these Keithley meters?
Cheers,
Great efforts Ian….thorough as always in working through all those faults. Can you tell me what was the part number for the power mosfet in the the pre-regulator….?
There are a couple different ones used, but the one to hand is a 2SK1451
Good work.
epic repair
Please show calibration! Love the videos, thanks.
Great job!!
Excellent repair journey, thanks for sharing! Looking forward to seeing the calibration vid.
One question: why did the (uncalibrated) reading vary so much when you slowly changed the line voltage?
Is the 230V line voltage directly controlling the unregulated +/-8V supply?
There's a fault with the analogue board. I am working on it.
I had no doubt you would get it working, just how many Parts 6,7,8,9 ... would it take. *_Cheers_*
Ian did you remove the auto voltage select circuit to prevent the unit self destructing in the future?
Brilliant repair and very entertaining.
2 reasons I removed that function:
1. To stop future self destruct.
2. Not easy to isolate the circuit in order to repair and test, even if I could have done it how reliable are the relays etc.
I for one would've loved to see it being calibrated.
Epic repair, not many would try with such so much damage with a massive voltage overload which takes out fixed regulators, well done. Any idea what the root cause of the over-voltage was? i.e what failed in the voltage selection circuit or theories?
I am thinking leaky caps on analog board took out the DC supplies somewhat, which then affected the 120/220Vac logic.......and then BANG!
I new those 4 DVM bench meters would come in handy - You enjoyed the repair wow you enjoy punishment LOL. I know I guy that has two Solarton 7075s that dont work?
My fluke DMM's only ever get used when I am doing this sort of multi-voltage monitoring. Very handy!
I know a guy also that's got a couple of 7075s that he'll be working on soon.
Please show us the calibration...
👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏 Great, Ian!
Shame about the original board, because one of the other vids with the finding and replacing of lots of failed ICs was pretty interesting.
Do I have new competition for the mammoth repair series genre ? LOL
Naw!, I am stopping at 6 in this series.....irrespective of how much fun it was. Talk about rabbit holes!
and PLEASE show us the calibration
Dude , how are your lucky charms?
lesson learned...don't buy one of these LOL, what a nightmare