Ian, just noticed your channel. I am a retired EE and I pride myself on troubleshooting. I must tell you - I wish I had had the opportunity to hire you when I was working. Your thinking, technique, and skills are #1. Good for you - not to mention a reasonable job of creating a video. You gain a viewer. dan
I began working in EE in the 80's......hardly any tools, just a 2000 count DMM and a 20Mhz scope......but we had to fix all sorts or we never got paid.......I certainly learned my trade back then. Good times!
@@IanScottJohnston Well happy to have bumped into you. I am awaiting a 'new to me' instrument. A beast. HP3562a which is faulty. "No Display' - Usually one of the easy type repairs - but like your DMM it could also be a nightmare. All the best.
@@IanScottJohnston Just another note: this June my wife, and myself along with another couple are flying over the pond to see the UK and Ireland. I'll keep an eye out for you :-} (as long as putin - well we won't think about that for a bit.) I guess I assume you are British. I am American, but not so proud anymore. Glad the orange one is history.
@@IanScottJohnston Very good! We visited Scotland about 10 years ago. Beautiful, I still retain a coveted bottle of Scotch from the Edradour Distillery. Damn it is not imported to the USA. We also visited Islay distilleries among others. Good memories.
At a complete guess, I am thinking the pre-regulator circuit went haywire and subjected the regulator(s) to abnormally high incoming (uggghhh!). We'll see when i get to the analogue board. The hot air gun attachments are great, and a must on 6 layer boards! Igot two sizes.
Excellent work! I have my fingers crossed hoping there aren't too many more issues! I was lucky enough to pick up an HP 4338A Milliohmmeter a while back (cheap -$270 US) that is really helpful in situations like this. Looking forward to part 2.
You certainly did get a great deal on this. Well done. The repair is going really well. That was a lot of faults to find. I need to start using the power to ground resistance more thoroughly. That’s a powerful technique.
Lol. That chip really was a strong performer for worst soldering job on an expensive device category. I was watching on my phone and I had to cast it up to the 4k TV to be sure. Yup, was what it appeared to be. 🤷🏻♂️
Oh boy why did I watch this video? I have a 2015 and a 2001 both second hand. I should man up and at least eyeball the caps. Epic repair video - can't wait till part 2!
If you don't have a special QFP hot air attachment for that particular pin arrangement an alternative is to carefully cut the legs off from the top edge of the chip with a sharp scalpel. Throw the bug away and use a soldering iron and braid to remove the remaining legs from the pads. ETA: Great video BTW. I am looking forward to this very interesting repair!
For boards with lots of layers and/or those with large fills and component pads with no thermal isolation, preheating the PCB works wonders. I have a small 350W heat gun I keep on my bench for heat shrink tubing. It also does a great job preheating a PCB. Go over the top and bottom of the component area of the PCB, heat to 100C or so and then remove the bad part.
I'm impressed at how you were able to remove the processor. It's nice to have an adapter to make that so much easier. Also the trick about how many layers the board has was neat too.
That thing received some serious abuse, it appears, even if it looks very good inside. Amazing job! Looking forward to the next episode. That will be a fantastic instrument.
Ah, IMSAI Guy! The first person I look for when I wake up and have a cup of coffee. Your content has become part of my morning ritual. Nice to see you out and about. You’ve had your own Keithley Multimeter fun lately.
I can only guess what caused it at the moment. What worries me is the pre-regulator circuit on the incoming AC side.....it's kind of novel.....but if it goes wrong it sends high secondary voltages everywhere....ugghh!
@@IanScottJohnstonI don’t really understand the novel preregulator you speak of, but the ceramic resistor has a thermal fuse and fails open circuit (assuming I’m thinking of the correct circuit). I wonder why did they design it like that? There is some clever reason for it, or it’s just an obscure design?
Fascinating stuff as always. I need content like this so I have something to keep me sane when I am not feeling well enough to be at my own workbench tinkering away. Looking forward to part 2. 👍
Hi Ian, another super video, full of good stuff. I am a (semi)retired repair tech with nearly 50 years experience so have encountered a number of these type of problems. Over the years I have found the EDS Leakseeker 82B absolutely invaluable for diagnosing exactly this type of problem, It is way way more than just a low ohm meter, which are only really of use on shorts or very low ohm leaks, maybe add one to your armoury?. Was very impressed with the CPU replacement on such a tricky board. The "heat" marks on the analogue board look more like flashover residue on my monitor. Thanks again for some great videos, Mike
I often do not have the right baffle for my hot air smd remover to fit a particular TQFP. What I often do is cut the pins off the package first, dispose of the chip, and then desolder the pins from the PCB with wick. To cut the pins, I have had great success at shearing them close to the package with a very sharp knife. This seems to put less stress on the PCB than using diagonal cutters. On a 12 layer PCB I worked on at a major company, this cutting the pins method also had better success than trying to get the chip off without lifting a pad than other methods to replace a batch of bad ASICs. I also have some metal picks (pointy probes, kind of like dental tools only longer) I use when working on various things. One with a slight bend to it is really handy for desoldering with the hot air system. The pick will slide under the package much easier than a tweezer or pliers, and allow you to pick up the device like you show. The nice thing is that it works in small spaces and avoids having the hot solder-laden part slide around on the board. Another nice tool I have been using since my tube (valve) days is a fiberglass screwdriver. I make my own from stock rods, and they don’t steal heat away for various tasks. They also don’t conduct and don’t seem to cut small traces. Just take appropriate health cautions when grinding the tips. Pointy ones are handy, too.
29:00 Another easy way to get such chips (of any size) of a board, is just cut the legs. Have to be careful that you dont slip and cut the PCB, but its a good way of removing destroyed tqfp packages of any size without needing specialty tools. After the chip is cut, you can use a regular soldering iron + wick to clean up the remains of the legs and the pads.
Those inverter transistors being blown is very worrying, it would take a lot more than a few extra volts to take them out. Good luck with this, I will watch your progress with keen interest. If the same 5v line is shared with the analogue board then I would do a quick resistance check on that as well, If you find shorts to ground then I think you need to reassess.
The transformer is intact so doubt it was a high Ic, more likely Vebo (Abs. max=5V) which blew those transistors. I have a plan for the analogue board once I get to it......stay tuned.....:-)
Very nice! I had to chuckle a little, I worked for Keithley Instruments from 1997-2014. I maintained the firmware for many models, including the 2001. I was probably the one who made that B17 firmware release.
Have to think any device connected to the 5V supply has been extremely stressed and it's days are numbered. May be worth replacing as many silicon fuses as are easy and cheap to get. Very brave to takle this repair and good luck, look forward to next installment. Impressive job so far, and agree the IR camera is priceless.
@@IanScottJohnston Takes me back 40 years working in a microwave and test equipment repair centre, more analogue and less digital, but have sort of kept up to date over the years. Thanks to Marco Reps inspirational videos, recently now the owner of eBay purchase, discarded labelled "scrap" 2008 Agilent HP34401A "MY" serial number, going over all the circuits, replacing electros, tantalums and updating some of the IC parts. I've found increasing the size of the main regulator caps reduced the pre ripple and noise, always helpful in a precision measurement device. Putting a 2022 eye over the 20 something year design is interesting. Many thanks to all the repair videos and supporting PC software for the 34401A. PS I've been looking at the new ADR1399 as a reference replacement i.e. poor man's LTZ1000 but still worthwhile.
I'm impressed with your determination. When I find a short on the VCC line of a logic board I groan. I pull all the pluggable parts, it's never them, replace the decoupling caps and check all the protection diodes - it's sometimes them and then usually give up if no luck at that point. It seems that nearly every time I've tried to go for the lowest resistance point it has not been that or like you've experienced here, it's not just that part.
Yep, it can be frustrating and I find there are a few ways to resolve a short:- 1. Resistance check 2. Thermal camera 3. Gut instinct, luck & experience. All three have equal weight........
I think the a previous repair shop gave it to the junior to swap that opamp lol! It was shockingly bad! OMG at how many parts were bad so far!!!!!! Overvoltage from hell! Really looking forward to the next part! I think I would be tempted to modify that board and add a fuse on the 5v rail...
you find the best stuff for good repairs , when ever i look on ebay i never find them... so far :). I am pretty confident your going to lick this one too, cant wait for part 2. keep up the excelent work
Great video can't wait for the next part. We used to have a dc current tracer probe back in the 80’s which could tell which way the current was exiting the junctions, work well on two layer PCB’s god knows how it would have coped with 6 layers. After that we had a IR spot meter and a calibrated engineers finger. The hrs spent looking for a microphonic component in the audio circuit buy hitting it with a rubber tipped pencil, you tell that to the kids today and they won’t believe you. Was not as much fun when we went to time division multiplexed digital audio control, all the rubber tipped pencils were just used for drawing after that. :-)
Aye, back in the 80's we were offered current tracers, but the boss asked "if you need one your troubleshooting skills can't be up to much".......so we declined! I was always a bit meh! with them, I didn't think they were that good....never did find out either way. Heck, in the 80's we didn't have the luxury of thermal cameras either! My finger has been long overdue calibration.
@@IanScottJohnston I looked at building an ATE rig mid 80's, the rack mount DVM and the switching matrix were 1/2 the cost of my first house. boss said it t speeds up testing go for it, built two in the end. :-) Happy days. I have an HP 5 1/2 and a HP 6 1/2 digit, might have to make room for a 7 1/2 digit someday.
hi Ian, 29.50 that kind of board is better to preheat all the board (hotplate), and them remove ic, the heat stress is less that way. and very more easy to extract ics. :)
It should be OK on the digital board, but it's not the kind of thing you'd want on the analogue board. The hot air gun attachment should keep the heat fairly well contained
Ahhhh!....so it is!......I was so deep into the why's at what for's it went right over me....cheers! I'll mention at the next video. It's generating 60Vdc I have since found out.
o my this is so interesting... keithiey makes cool stuff, they needed more sales and test equipment as fluke is everywhere.. time for coffee and watch the show 😊 thanks sweet 7.5 digit meter... back in the days when the free world could make quality things🌻 could be the 5vdc got shorted out from the person trying to fix the meter?
Great set of videos! At 18.58, you mentioned that you discussed in a previous video the technique of measuring various components and various sections of a board to find the source of a short. Would you mind telling us which video that is? Thank you.
..... I concur, but he loves the detective work, and has the knowledge & persistence to press on. If I'm ever marooned on a desert island with a smashed transmitter, I want ISJ as company (not Gilligan !) . P.S. and a decent Digital multi meter.
Hi, I just got a 2001 with “Overflow ACV” on the display. Any clues on how to start troubleshooting this failure? Thanks for any help provided. Also, is the xdevs site one of the better ones for schematics, material list, calibration, etc?
Nice! How do you think all this happened? Overvoltage on the inputs, or that 5V regulator "caving in" ? I also use a current limited supply for fault finding in such cases. A thermal camera is great, I will get one. In my experience, electrolytics don't _need_ to be bad, it depends much on working temperature and time the kit has been in use. An ESR meter can spot bad ones easily
I think the pre-regulator on the PSU probably folded sending a high unreg DC to the regulators....possibly. There is a know issue of the 2001 experiencing leaky caps in the 90's , probably from a bad batch. Most people repairing them dont take any chances given the value of the instrument.
.... Well done Mate, Einstein of electronic diagnostics, must be related to James Clerk Maxwell. Is that the Flir C5 ? ? I have the C5, are you using a '20mm CO2 Laser ZnSe Focal Lens' ? ? ? ? Looked more impressive than what I get ? ?
It's an old Flir C2 that i bought used via Ebay. I modified it so I could do close ups and still have the optical and IR lens align properly. I think theres a video on my channel of my mods.
@@IanScottJohnston .... Still the parallax issue, I'm going to try a ZnSe 100mm focal length covering both cameras. They are cheap, AU$30 so nothing to lose. P.S. Uni-T have some higher res. per $ products. I would likely go down that path next time. (and the Flir logo pisses me off !).
so, i had to watch the whole 40 mins of your arizona accent (accelerated speed), and then had to spend a very long time going through all your replies, and still can't find the most important bit of info that should've been in the title, how much did you pay for it? and where did you buy it? ebay? are you escaping taxes or something?!
Very nice! It's rare not to find any leaky caps, congrats 🎉
Especially in a 2001 by all accounts!
Wow, IMSAIguy and now Mr. Voltenstein himself! In your comments! You’re kind of like the latest celebrity chef to the stars! Very cool.
Ian, just noticed your channel. I am a retired EE and I pride myself on troubleshooting.
I must tell you - I wish I had had the opportunity to hire you when I was working. Your thinking, technique, and skills are #1. Good for you - not to mention a reasonable job of creating a video. You gain a viewer. dan
I began working in EE in the 80's......hardly any tools, just a 2000 count DMM and a 20Mhz scope......but we had to fix all sorts or we never got paid.......I certainly learned my trade back then. Good times!
@@IanScottJohnston Well happy to have bumped into you.
I am awaiting a 'new to me' instrument. A beast. HP3562a which is faulty.
"No Display' - Usually one of the easy type repairs - but like your DMM it could also be a nightmare. All the best.
@@IanScottJohnston Just another note: this June my wife, and myself along with another couple are flying over the pond to see the UK and Ireland. I'll keep an eye out for you :-}
(as long as putin - well we won't think about that for a bit.)
I guess I assume you are British.
I am American, but not so proud anymore. Glad the orange one is history.
@@mr1enrollment Scottish and damn proud.......:-)
@@IanScottJohnston Very good! We visited Scotland about 10 years ago.
Beautiful, I still retain a coveted bottle of Scotch from the Edradour Distillery. Damn it is not imported to the USA. We also visited Islay distilleries among others. Good memories.
Very impressive how you troubleshoot this digital board.
wow! that was an in-depth repair indeed. good luck!
Glad the hot air gun attachment worked so well. Makes you wonder what happened though!?
At a complete guess, I am thinking the pre-regulator circuit went haywire and subjected the regulator(s) to abnormally high incoming (uggghhh!). We'll see when i get to the analogue board.
The hot air gun attachments are great, and a must on 6 layer boards!
Igot two sizes.
Excellent work! I have my fingers crossed hoping there aren't too many more issues! I was lucky enough to pick up an HP 4338A Milliohmmeter a while back (cheap -$270 US) that is really helpful in situations like this. Looking forward to part 2.
Oh you lucky guy.......the 4338A is nice!
You certainly did get a great deal on this. Well done. The repair is going really well. That was a lot of faults to find. I need to start using the power to ground resistance more thoroughly. That’s a powerful technique.
Wow you certainly picked up a basket case there! OMG the soldering on that IC was horrific! Good luck for the next part!
As I am sure you understand with your repairs.......I wouldn't have it any other day!, i.e. where's the fun in replacing bad caps...LOL!
Lol. That chip really was a strong performer for worst soldering job on an expensive device category. I was watching on my phone and I had to cast it up to the 4k TV to be sure. Yup, was what it appeared to be. 🤷🏻♂️
Oh boy why did I watch this video? I have a 2015 and a 2001 both second hand. I should man up and at least eyeball the caps. Epic repair video - can't wait till part 2!
If you don't have a special QFP hot air attachment for that particular pin arrangement an alternative is to carefully cut the legs off from the top edge of the chip with a sharp scalpel. Throw the bug away and use a soldering iron and braid to remove the remaining legs from the pads.
ETA: Great video BTW. I am looking forward to this very interesting repair!
That particular package has quite long legs to the pins......snipping should be easy.
For boards with lots of layers and/or those with large fills and component pads with no thermal isolation, preheating the PCB works wonders. I have a small 350W heat gun I keep on my bench for heat shrink tubing. It also does a great job preheating a PCB. Go over the top and bottom of the component area of the PCB, heat to 100C or so and then remove the bad part.
I'm impressed at how you were able to remove the processor. It's nice to have an adapter to make that so much easier. Also the trick about how many layers the board has was neat too.
Thanks!
Great effort Ian! Looking forward to Part 2! Hope it all comes good.......
That thing received some serious abuse, it appears, even if it looks very good inside. Amazing job! Looking forward to the next episode. That will be a fantastic instrument.
When I measured that first short circuit it was then I realised it had been through the wars. Great fun though!
Sadly, I think this one got it’s abuse by a “Dr.” Practicing without a proper license and not by a user as we’d expect.
Now this is a formidable challenge! Great work on the debugging AND in finding those old parts. Looking forward to part 2, 3, 4,.....
Yep, who knows what is in store for me when I hit the analog board!
A lot to bite off, good luck, those are expensive meters and will be great to get it going. looks like a cascade failure, wonder what went wrong first
Ah, IMSAI Guy! The first person I look for when I wake up and have a cup of coffee. Your content has become part of my morning ritual. Nice to see you out and about. You’ve had your own Keithley Multimeter fun lately.
I can only guess what caused it at the moment. What worries me is the pre-regulator circuit on the incoming AC side.....it's kind of novel.....but if it goes wrong it sends high secondary voltages everywhere....ugghh!
@@IanScottJohnston did you find schematics?
@@IanScottJohnstonI don’t really understand the novel preregulator you speak of, but the ceramic resistor has a thermal fuse and fails open circuit (assuming I’m thinking of the correct circuit).
I wonder why did they design it like that? There is some clever reason for it, or it’s just an obscure design?
Fascinating stuff as always. I need content like this so I have something to keep me sane when I am not feeling well enough to be at my own workbench tinkering away. Looking forward to part 2. 👍
This one is going to make you work. Quite the hunt. I can tell you love it though. I'm looking forward to seeing it come back to life.
Epic repair this one has turned out to be, cant wait for part two now!
I'm keen to get on with it myself!.....waiting on some hard to find parts to arrive......dang!
Great troubleshooting here Ian 👍
Hi Ian, another super video, full of good stuff. I am a (semi)retired repair tech with nearly 50 years experience so have encountered a number of these type of problems. Over the years I have found the EDS Leakseeker 82B absolutely invaluable for diagnosing exactly this type of problem, It is way way more than just a low ohm meter, which are only really of use on shorts or very low ohm leaks, maybe add one to your armoury?. Was very impressed with the CPU replacement on such a tricky board. The "heat" marks on the analogue board look more like flashover residue on my monitor. Thanks again for some great videos, Mike
Thanks for the comments, I'll see if I can pick up an 82B, would certainly help to speed up diagnosis.
I often do not have the right baffle for my hot air smd remover to fit a particular TQFP. What I often do is cut the pins off the package first, dispose of the chip, and then desolder the pins from the PCB with wick. To cut the pins, I have had great success at shearing them close to the package with a very sharp knife. This seems to put less stress on the PCB than using diagonal cutters. On a 12 layer PCB I worked on at a major company, this cutting the pins method also had better success than trying to get the chip off without lifting a pad than other methods to replace a batch of bad ASICs.
I also have some metal picks (pointy probes, kind of like dental tools only longer) I use when working on various things. One with a slight bend to it is really handy for desoldering with the hot air system. The pick will slide under the package much easier than a tweezer or pliers, and allow you to pick up the device like you show. The nice thing is that it works in small spaces and avoids having the hot solder-laden part slide around on the board. Another nice tool I have been using since my tube (valve) days is a fiberglass screwdriver. I make my own from stock rods, and they don’t steal heat away for various tasks. They also don’t conduct and don’t seem to cut small traces. Just take appropriate health cautions when grinding the tips. Pointy ones are handy, too.
29:00 Another easy way to get such chips (of any size) of a board, is just cut the legs. Have to be careful that you dont slip and cut the PCB, but its a good way of removing destroyed tqfp packages of any size without needing specialty tools.
After the chip is cut, you can use a regular soldering iron + wick to clean up the remains of the legs and the pads.
Those inverter transistors being blown is very worrying, it would take a lot more than a few extra volts to take them out. Good luck with this, I will watch your progress with keen interest. If the same 5v line is shared with the analogue board then I would do a quick resistance check on that as well, If you find shorts to ground then I think you need to reassess.
The transformer is intact so doubt it was a high Ic, more likely Vebo (Abs. max=5V) which blew those transistors.
I have a plan for the analogue board once I get to it......stay tuned.....:-)
Very nice! I had to chuckle a little, I worked for Keithley Instruments from 1997-2014. I maintained the firmware for many models, including the 2001. I was probably the one who made that B17 firmware release.
I bet you chuckled!…….thanks for posting, it’s great to hear from the developers of these pieces of kit.
Have to think any device connected to the 5V supply has been extremely stressed and it's days are numbered. May be worth replacing as many silicon fuses as are easy and cheap to get. Very brave to takle this repair and good luck, look forward to next installment. Impressive job so far, and agree the IR camera is priceless.
I love these types of repair......takes me back 20-years when I was working on digital/analogue designs in the oil industry.
@@IanScottJohnston Takes me back 40 years working in a microwave and test equipment repair centre, more analogue and less digital, but have sort of kept up to date over the years.
Thanks to Marco Reps inspirational videos, recently now the owner of eBay purchase, discarded labelled "scrap" 2008 Agilent HP34401A "MY" serial number, going over all the circuits, replacing electros, tantalums and updating some of the IC parts. I've found increasing the size of the main regulator caps reduced the pre ripple and noise, always helpful in a precision measurement device. Putting a 2022 eye over the 20 something year design is interesting.
Many thanks to all the repair videos and supporting PC software for the 34401A.
PS I've been looking at the new ADR1399 as a reference replacement i.e. poor man's LTZ1000 but still worthwhile.
I'm impressed with your determination. When I find a short on the VCC line of a logic board I groan. I pull all the pluggable parts, it's never them, replace the decoupling caps and check all the protection diodes - it's sometimes them and then usually give up if no luck at that point. It seems that nearly every time I've tried to go for the lowest resistance point it has not been that or like you've experienced here, it's not just that part.
Yep, it can be frustrating and I find there are a few ways to resolve a short:-
1. Resistance check
2. Thermal camera
3. Gut instinct, luck & experience.
All three have equal weight........
I think the a previous repair shop gave it to the junior to swap that opamp lol! It was shockingly bad! OMG at how many parts were bad so far!!!!!! Overvoltage from hell! Really looking forward to the next part! I think I would be tempted to modify that board and add a fuse on the 5v rail...
The analogue board is gonna be fun......a lot more electronics!
I love these types of videos. Commenting as you go. Brilliant stuff mate!
I used to train all the junior electronic techs years ago on the job......I can't help but do it that way.......it's just me...:-)
Really looking forward to PT2
you find the best stuff for good repairs , when ever i look on ebay i never find them... so far :). I am pretty confident your going to lick this one too, cant wait for part 2. keep up the excelent work
thanks for another great learning video..I enjoy these alot.
Wow Amazing video as others had said that is much more work than I would be prepared for. But great work.
Great video can't wait for the next part. We used to have a dc current tracer probe back in the 80’s which could tell which way the current was exiting the junctions, work well on two layer PCB’s god knows how it would have coped with 6 layers. After that we had a IR spot meter and a calibrated engineers finger. The hrs spent looking for a microphonic component in the audio circuit buy hitting it with a rubber tipped pencil, you tell that to the kids today and they won’t believe you.
Was not as much fun when we went to time division multiplexed digital audio control, all the rubber tipped pencils were just used for drawing after that. :-)
Aye, back in the 80's we were offered current tracers, but the boss asked "if you need one your troubleshooting skills can't be up to much".......so we declined! I was always a bit meh! with them, I didn't think they were that good....never did find out either way. Heck, in the 80's we didn't have the luxury of thermal cameras either! My finger has been long overdue calibration.
@@IanScottJohnston I looked at building an ATE rig mid 80's, the rack mount DVM and the switching matrix were 1/2 the cost of my first house. boss said it t speeds up testing go for it, built two in the end. :-) Happy days. I have an HP 5 1/2 and a HP 6 1/2 digit, might have to make room for a 7 1/2 digit someday.
I love your channel.
You have fascinating content.
Ian, awesome as usual. Thank you!
Great video! Super interesting repair. What a trainwreck that board was ¬¬
Great work Ian ! 'low balled them' ' so 50 - 60 quid ? I look forward to part 2...cheers.
50 - 60 quid!........I wish!........but not that far away.
hi Ian, 29.50 that kind of board is better to preheat all the board (hotplate), and them remove ic, the heat stress is less that way. and very more easy to extract ics. :)
Ian, great job. As always ;) Keep the good work!
It also helps to have a hot plate when desoldering packages from a board with large copper pours under devices.
It should be OK on the digital board, but it's not the kind of thing you'd want on the analogue board. The hot air gun attachment should keep the heat fairly well contained
The high voltage supply is a saturating Royer oscillator.
Ahhhh!....so it is!......I was so deep into the why's at what for's it went right over me....cheers! I'll mention at the next video. It's generating 60Vdc I have since found out.
What a task,well done!
o my this is so interesting... keithiey makes cool stuff, they needed more sales and test equipment as fluke is everywhere.. time for coffee and watch the show 😊 thanks
sweet 7.5 digit meter... back in the days when the free world could make quality things🌻 could be the 5vdc got shorted out from the person trying to fix the meter?
Very nice! It's a great hobby.
Another good channel , thanks
Great set of videos! At 18.58, you mentioned that you discussed in a previous video the technique of measuring various components and various sections of a board to find the source of a short. Would you mind telling us which video that is? Thank you.
No. 35 in my videos.
Years ago I worked with its Big Brother, the Keithley Electrometer. Sub pA current detection. To my mind it was just black magic.
Nice video indeed. a lot of work..i think i would give that one up..it is too much work ..
..... I concur, but he loves the detective work, and has the knowledge & persistence to press on.
If I'm ever marooned on a desert island with a smashed transmitter, I want ISJ as company (not Gilligan !) .
P.S. and a decent Digital multi meter.
Try using some flux around the large parts before heating.....Refer to some of Louis Rossman's repair videos.
Hi, I just got a 2001 with “Overflow ACV” on the display. Any clues on how to start troubleshooting this failure?
Thanks for any help provided.
Also, is the xdevs site one of the better ones for schematics, material list, calibration, etc?
I keep wondering if I should get a Keithley 7001 switch and repair it. They look the same as the 2001.
I wonder if someone went and used a wonky RS232 cable to kill the 5v on the board which took out plenty of stuff.
We must be mad to try and fix these things. Unfortunately I’m just the same. I would have check that capacitor to ground in the crystal circuit
Unfortunately, the capacitor is fine......which left only one conclusion. Mind you, in all my years, i've never seen a uP xtal pin shorted like that.
Nice! How do you think all this happened? Overvoltage on the inputs, or that 5V regulator "caving in" ? I also use a current limited supply for fault finding in such cases. A thermal camera is great, I will get one. In my experience, electrolytics don't _need_ to be bad, it depends much on working temperature and time the kit has been in use. An ESR meter can spot bad ones easily
I think the pre-regulator on the PSU probably folded sending a high unreg DC to the regulators....possibly.
There is a know issue of the 2001 experiencing leaky caps in the 90's , probably from a bad batch. Most people repairing them dont take any chances given the value of the instrument.
good video
Any idea who made the first 7.5-digit multimeter? I'm thinking it may had been Datron with the 1071.
Not really sure. There are a few but possibly the Datron is the oldest.
Great strip down and fault finding, I hope you got it cheap enough as I am sure there will be a few more problems I look forward to part 2 🙂
Squeak !!!!!!!!!!!!!!!!!!!!!!!!!
@@andymouse peanut butter!!!!
@@fredflintstone1 The force is strong with you ! mousey's love the stuff.
@@fredflintstone1 never found out out they get butter out of a non-nut. Pealegume does not have the right ring to it. :-)
@@TheEmbeddedHobbyist Heck you want to try milking an Almond man that is hard 🙂
Why is there an 8 pin dip socket without an IC, especially if the layout provides place to fit a16 pin dip package?
It's two 8-pin DIP side by side. U632, U633. Two optional I2C Eeproms only used on the 2002 model (8.5 digit) which shares the same digital board.
A consummate repair - so far
.... Well done Mate, Einstein of electronic diagnostics, must be related to James Clerk Maxwell.
Is that the Flir C5 ? ? I have the C5, are you using a '20mm CO2 Laser ZnSe Focal Lens' ? ? ? ? Looked more impressive than what I get ? ?
It's an old Flir C2 that i bought used via Ebay. I modified it so I could do close ups and still have the optical and IR lens align properly. I think theres a video on my channel of my mods.
Flir C5 = IR sensor 160 × 120 (19,200 pixels)
Flir C2 = IR sensor 80 x 60 (4800 pixels)
.....so the C5 should be MUCH better. Would love to try one.
@@IanScottJohnston .... Still the parallax issue, I'm going to try a ZnSe 100mm focal length covering both cameras. They are cheap, AU$30 so nothing to lose. P.S. Uni-T have some higher res. per $ products. I would likely go down that path next time. (and the Flir logo pisses me off !).
wow...what a disaster...I would be surprised if those two SRAMs survived this.
Decided to leave them on the board till i power up properly. Got spares on standby.
Input switch normally goes dicky........ cracking meter though
crap ic scokets
so, i had to watch the whole 40 mins of your arizona accent (accelerated speed), and then had to spend a very long time going through all your replies, and still can't find the most important bit of info that should've been in the title, how much did you pay for it? and where did you buy it? ebay? are you escaping taxes or something?!
Arizona accent? Lol wut
I was sure he said where he bought it