Many states and locales regulate the use of these x-ray machines so you have to get a license to use them. Ben Krasnow got a call from the California regulators after his video where he was trying to build a CT scanner. These PBC x-rays do pop up used from time to time, especially the older film bases ones.
It nice to watch a repair video from someone that has a professional repair stance, alot of the videos from the fly by night mobile techs are an insult to watch as a professional, or anyone with proper training. You sir got it goin on, I tip my hat to you.
I have the big brother AC source, Chroma 61705 at work, 12000VA. Good job on the repair investigation. I feel like I follow these a bit better than your more technical videos :)
The GW-Instek front panel seems incorrectly labelled for a UK mains plug. In this plug, the live is on the right. Upside down (as the plug would need to be) it is therefore on the left, which is marked "N". Great video - always find the repair ones interesting, I particularly value the way you talk through your reasoning. Thanks.
Wow. That’s a nice unit. I managed to get one of those Sencore units and that works well for my applications, but this unit provides a lot more control and measurement . I like your use of the thermal imager. I picked one of those up from the Keysight eBay site a couple of years ago, and it is a great tool for troubleshooting.
"... $400 which is not cheap..." at :58. Cheaper than any scope probe or other cable mounted accessory from Keysight! The best used AC / DC power supplies are, if you can find them, from Kikisui. To match your other test gear, emtest has some 4 quadrant programmable supplies which can source / sink power. Like the Keysight stuff, if you have to ask the price, you can't afford it (hint made in Switzerland, >$10,000).
Nice, I watched your repairs from the very first one many years ago and I'm fascinated how much more possibilites you got now. It seems that you have so many fancy and advanced ways of troubleshooting, that there is no error you can't find within a few hours. This also shows a lot of out of the box ways of thinking about something which is very nice. Greetings, Michael
14:49 Loved the Pooch cameo. Great repair as always! I always learn something from your repairs. Out of interest were you able to track down a wire bonder for one of your earlier challenging repairs? Cheers!
Nice work. Perhaps you could film all the actual ic removal and probe connection stuff or perhaps some snippets. I am sure curious how you do some of those things. I seem to spend ages making reliable interboard connections as I never seem to have the right type of pin or socket on hand so try to make them with copper wire and solder.
@@Thesignalpath No worries, I just had the bad luck of clicking on it exactly when you pulled it. I just finished watching the entire thing, great video as always!
Probably the failing negative voltage regulator allowed the input to exceed the supply voltage, and the IC's latched up and started to draw a heavy current through the internal junctions, as the parasitic SCR structure turned on. This then damaged the junctions and made for high leakage in there, or shorted out internal transistors, and thus the power draw.
I was wondering if that flaky -5 Volt regulator was somehow responsible. The APS-1102 is retired. Maybe the GW-Instek engineers have seen this failure before...
The unit has been discontinued. Maybe that's why 3 Opamps could be defective at the same time. Redesign for reliability maybe an interesting next episode.
Hi Shahriar, thank you for this very educational video and walk through as always. Could you provide some references to learn more about the voltage regulator ageing? I'd like to learn about the fundamental phenomena that drives the ageing and whether this impacts other types of ICs. One of the problems I often face at work is needing to buy parts from the open market to cover shortages - these parts can be several years old. We only qualify the parts by checking MSL, solderability, and functional (feature) testing. Thanks in advance!
When I need to do serious reverse engineering on a board I like to use GIMP. I will take a picture of the front and back of board, put them on separate layers in GIMP and adjust the transparency to get get a view of both sides at the same time. I have one more layer added to trace lines and make notes. Having a layer to add an X-ray view would definitely be nice.
I wonder what may have caused three opamps on the same power supply to blow up. My guess is that there was a spike on their power supply due to aging voltage regulator - enough to momentarily exceed maximum voltage these amps can take and blow them up.The fourth opamp survived other due to some additional serial filtering on its power supply or just being a little more tolerant because of natural manufacturing variation. What do you think?
@@BruceNitroxpro Why? Is it not possible that only these 4 opamps were powered by this +/- 5V power supply? Or the other components there were more resilient to overvoltage?
It assume for the serial connection just the DB9 connector has to be soldered / mounted. It looks like the level converter chips are already soldered to the board.
No idea where one would use this. Maybe testing in development? To precisely measure how a product will behave? To test whether a charger or razor will work with cheap converters? I'd like to know. It's beautiful.
Haven't watched the entire video yet but I noticed that coin cell. Is it alkaline? (edit) great video! I can follow a smart power supply repair a lot easier than some of the high end RF units but I love them all!
How are the “power amps” that are shown in the block diagram implemented? I’m guessing they must be some kind of high frequency switching converters with good filtering, since they make such a clean waveform in the output. Linear amplifiers would surely dissipate too much power in this application.
Roger on the LCD, but reliable low level tools DONT wnat to have tricksy high level control software that can crash on you Bit of colour might be nice though
@@tommihommi1 Hmm that's debatable- it sounds like more software complexity, which always involves more risk, methinks.... But ok maybe test eqpt manufacturers dont employ very visual programmers ;)
@@rogerstorrs8679 You just develop a GUI framework once, and then every instrument that has a screen can use the same style of GUI, it's relatively minimal development cost. You're running windows embedded or some *nix anyways, the stuff to build good GUIs all is there already. This device has an ugly GUI because it's much older than it looks, the plastics just didn't yellow.
What high voltage differential probe is that ? In the video it says "fully isolated", but the ones I know are not isolated. They have high impedance to ground ( like severa MOhms ) but they are not galvanically isolated.
Never expected to see a commercial instrument from a reputable brand with a universal plug of dead (A European two plug power lead fits diagonally across live and earth with the pins still exposed during contact)
Do you have any idea where to obtain the QL3004-0PFN100C FPGA placed on the control board, or a replacement board? The IC apparently has to be programmed so buying one from a random source is not an option.
We would never have another GW-Instek instrument of any kind after our past experiences with them. Their equipment is so very unreliable, going wrong at some point is the normal for this make. It's totally pot luck as to whether what you have from them will last or not :(
@@simontay4851 of course it can fit. 5A programmable AC. That device is huge, a single board that size could fit 10 of them. Google CE+T little box challenge.
Thanks, great debug video. Those 3 parts were 90C. And you knew something was drawing a lot of current. A thermal camera is great, but a wet finger or a $20 IR thermometer would find the problem parts pretty quick. Did you say what the parts were? And any theory about why they croaked? Design stress, excess input voltage or output current? 5V op-amps on +/- 5V? Weird load fault? A stray screwdriver? Counterfeit op-amps? Mystery continues...
Thanks, I agree. I repair a fair amount of stuff that turns out to be bad 78xx or 79xx regulators. Most electronics has a cushy life: regulated supplies, no real heat. It's the regulators that get hot and have to deal with voltage surges. What kind of op-amps were they?
@@liam3284 5amps, h bridge, it could probably be done for 100$ but then you can adjust the price depending on market size. Off the top of my head I would think you'd want to combine it with DC supply functionality so you don't have to have multiple product lines. Bigger market. You can have various complex software functionality but that's software, no BOM. CPUs are powerful while costing nada.
@@Thesignalpath I'm sure there is as a high-end piece of test gear, but I couldn't help but remember using a powerful rackmount A/B power amp to get a clean 50hz AC using just a sig-gen. Most good amps are DC coupled and will happily amplify DC too if fed and blocking protections bypassed. I remember it had some +/- 180VDC rail config and I couldn't lift it myself. Of course all of this can easily be done in some type of class-D config at 1/20th the size nowadays.
You did excellent fancy repair using all these instruments but I may say you are TOOOOO MUCH sensitive to the aging issue and no need for that replacement ....
"We need to X-ray this board". I can practically hear the sighs from around the world as thousands of viewers think "Damn... I wish _I_ had an x-ray"
Although the thermal image was far more helpful, as it directly diagnosed those OP amps to be dead.
Many states and locales regulate the use of these x-ray machines so you have to get a license to use them. Ben Krasnow got a call from the California regulators after his video where he was trying to build a CT scanner. These PBC x-rays do pop up used from time to time, especially the older film bases ones.
Nothing more satisfying than a well regulated power supply.
It nice to watch a repair video from someone that has a professional repair stance, alot of the videos from the fly by night mobile techs are an insult to watch as a professional, or anyone with proper training. You sir got it goin on, I tip my hat to you.
Very useful bit of kit. Excellent repair!
Wow, a Sencore PR57 on your bench! I'm impressed!
I have the big brother AC source, Chroma 61705 at work, 12000VA. Good job on the repair investigation. I feel like I follow these a bit better than your more technical videos :)
I'm quite certain this was actually made by NF Corporation in Japan for GW-Instek. It's basically a programmable power synthesizer.
Fantastic video as usual, thanks for all the really advanced electronics insights!
The GW-Instek front panel seems incorrectly labelled for a UK mains plug. In this plug, the live is on the right. Upside down (as the plug would need to be) it is therefore on the left, which is marked "N". Great video - always find the repair ones interesting, I particularly value the way you talk through your reasoning. Thanks.
Wow. That’s a nice unit. I managed to get one of those Sencore units and that works well for my applications, but this unit provides a lot more control and measurement . I like your use of the thermal imager. I picked one of those up from the Keysight eBay site a couple of years ago, and it is a great tool for troubleshooting.
Keep doing more repairs, I learn alot of techniques from you.. and man you have some really really kool toys.
woah thats some crazy piece of equipment
tablatronix , I must admit, it was a first for me. I usually don't live in the "fast lane" as far as this type of electronics goes.
That's a beautiful unit, and absolutely enormous! You mentioned it was large but still I was shocked to see the top-down view.
He's got a Hadron Collider in the back yard
T Komoski , And I have TWO! ROFL
uses it to light a Christmas light bulb!
I really enjoyed the video. Well done with your diagnosis and repair.
Yup, I need an X-ray rig too ! Thanks a lot for this video !
Nice!😀
Great instrument!
"... $400 which is not cheap..." at :58. Cheaper than any scope probe or other cable mounted accessory from Keysight! The best used AC / DC power supplies are, if you can find them, from Kikisui. To match your other test gear, emtest has some 4 quadrant programmable supplies which can source / sink power. Like the Keysight stuff, if you have to ask the price, you can't afford it (hint made in Switzerland, >$10,000).
shazam , TOTALLY true. "If you have to ask the price, you can't afford it." Like buying a yacht, right?
Nice look over! I have a GW function gen. Good stuff.
Nice, I watched your repairs from the very first one many years ago and I'm fascinated how much more possibilites you got now.
It seems that you have so many fancy and advanced ways of troubleshooting, that there is no error you can't find within a few hours.
This also shows a lot of out of the box ways of thinking about something which is very nice.
Greetings,
Michael
The IR camera I got for my phone was _the_best_ $400 I've ever spent on tools.
When my pal got his CAT phone we spent the afternoon with popping fuses in slo mo
I thought you meant it rhetorical, when you said you're going to x-ray the board. Nice repair video.
Very interesting video.
Only thing missing was running the unit at it's voltage, current and power extremes to verify operation.
Carry on.
Awesome video, thanks a lot!
Wooow how nice repair ! Great!
14:49 Loved the Pooch cameo. Great repair as always! I always learn something from your repairs. Out of interest were you able to track down a wire bonder for one of your earlier challenging repairs? Cheers!
Nice piece of equipment.
X-ray, thermal ... This is where Batman goes when something in the cave breaks down.
@@fosket What's that?
Nice job as every time of course!
X-Ray machine for troubleshooting, :D. Well done, as always.
Interesting! By looks of the front panel legend if you put a UK BS1363 plug in that socket the line and neutral connections would be reversed.
I'm under the impression the output is floating in which case it would be irrelevant.
It's unclear whether that would have any consequence in a completely isolated unit like this?
Nice thing there and it works in my frequency range
Nice work. Perhaps you could film all the actual ic removal and probe connection stuff or perhaps some snippets. I am sure curious how you do some of those things. I seem to spend ages making reliable interboard connections as I never seem to have the right type of pin or socket on hand so try to make them with copper wire and solder.
Looks like a lovely device....
Viewing x-ray images in MS Paint 😂
That's the future people were talking about decades ago. ❤
Ahh it's back up!
Sorry, something was wrong with the previous version.
@@Thesignalpath No worries, I just had the bad luck of clicking on it exactly when you pulled it. I just finished watching the entire thing, great video as always!
Why did all three opamp ICs fail? I would assume you figured this out, but you did not say in the video.
Probably the failing negative voltage regulator allowed the input to exceed the supply voltage, and the IC's latched up and started to draw a heavy current through the internal junctions, as the parasitic SCR structure turned on. This then damaged the junctions and made for high leakage in there, or shorted out internal transistors, and thus the power draw.
I was wondering if that flaky -5 Volt regulator was somehow responsible. The APS-1102 is retired. Maybe the GW-Instek engineers have seen this failure before...
A possibility for sure!
Nice fix! Good job :)
Great job!
The unit has been discontinued. Maybe that's why 3 Opamps could be defective at the same time. Redesign for reliability maybe an interesting next episode.
Hi Shahriar, thank you for this very educational video and walk through as always. Could you provide some references to learn more about the voltage regulator ageing? I'd like to learn about the fundamental phenomena that drives the ageing and whether this impacts other types of ICs. One of the problems I often face at work is needing to buy parts from the open market to cover shortages - these parts can be several years old. We only qualify the parts by checking MSL, solderability, and functional (feature) testing. Thanks in advance!
Aging is mostly caused by heat. I wonder how hot those regulators get in normal use.
When I need to do serious reverse engineering on a board I like to use GIMP. I will take a picture of the front and back of board, put them on separate layers in GIMP and adjust the transparency to get get a view of both sides at the same time. I have one more layer added to trace lines and make notes. Having a layer to add an X-ray view would definitely be nice.
dbinok , It must be nice to have a "GIMP inspired brain."
I do the same thing! It's really effective. I reversed a 160 BGA by doing this, though it took a while..
there's a couple of YT vids where people actually mill the PCB down layer by layer in a CNC, in front of a camera
I have no need for an X-Ray. I want an X-Ray.
I haven't seen a video from you in a long time.
@@gwc1410 Struggling to find the time.....🥵
You need an X-Ray.
I was just saying the same to my wife who was looking at me like “WTF!?!?”. LOL!
I wonder what may have caused three opamps on the same power supply to blow up. My guess is that there was a spike on their power supply due to aging voltage regulator - enough to momentarily exceed maximum voltage these amps can take and blow them up.The fourth opamp survived other due to some additional serial filtering on its power supply or just being a little more tolerant because of natural manufacturing variation. What do you think?
Adam Turowski , If so, there would be a few more things to be repaired/replaced before doing a full out and full voltage and current test.
@@BruceNitroxpro Why? Is it not possible that only these 4 opamps were powered by this +/- 5V power supply? Or the other components there were more resilient to overvoltage?
I am amazed of your skills to find cheap offers!! The only on eBay is used and cost about $3,000 right now! :-)
NF (a Japan company）also have a same power supply
Yes. This is just a rebadged NF product.
X-ray the PCB is the machine gun version of buzzing out the connections.
Machinegunning is using a wire brush as one of the electrodes, x-ray is the fragmentation grenade.
It assume for the serial connection just the DB9 connector has to be soldered / mounted. It looks like the level converter chips are already soldered to the board.
No idea where one would use this. Maybe testing in development? To precisely measure how a product will behave? To test whether a charger or razor will work with cheap converters? I'd like to know.
It's beautiful.
That thing has a noisy output and crappy sw but it is a beast for LV124 testing.
Nice device, i just have a simple adjustable transformer.
Fun
Oh come on, you should do a full teardown and show us all the internals!
Haven't watched the entire video yet but I noticed that coin cell. Is it alkaline? (edit) great video! I can follow a smart power supply repair a lot easier than some of the high end RF units but I love them all!
Did the differential between the +5 and -5 cause the op-amps to heat up because they were working overtime?
How are the “power amps” that are shown in the block diagram implemented? I’m guessing they must be some kind of high frequency switching converters with good filtering, since they make such a clean waveform in the output. Linear amplifiers would surely dissipate too much power in this application.
Most likely IGBT output stages just like VFDs.
Very often I think "oh such a device would be handy now", then I see what it costs and turn around...
Dennis Lubert , You, too? OMG... the prices are astronomical for many decent devices.
@@BruceNitroxpro Wait for one to go on sale
@@TKomoski , It's like wishing you were rich... LOL It ain't gonna happen!
@@BruceNitroxpro Or related to Shahriar
It's always weird when devices that look fairly modern when turned off have absolutely ancient GUIs when turned on
That particular style of LCD panel are quite unpleasant to spend much time looking at
Roger on the LCD, but reliable low level tools DONT wnat to have tricksy high level control software that can crash on you
Bit of colour might be nice though
@@rogerstorrs8679 A good looking gui isn't any less stable, and makes the user less prone to accidentally doing the wrong thing.
@@tommihommi1 Hmm that's debatable- it sounds like more software complexity, which always involves more risk, methinks....
But ok maybe test eqpt manufacturers dont employ very visual programmers ;)
@@rogerstorrs8679 You just develop a GUI framework once, and then every instrument that has a screen can use the same style of GUI, it's relatively minimal development cost.
You're running windows embedded or some *nix anyways, the stuff to build good GUIs all is there already.
This device has an ugly GUI because it's much older than it looks, the plastics just didn't yellow.
In what situations do you need AC source with DC offset?
No clue what killed the three opamps?
Planned obsolescence
@@anonymousarmadillo6589 , Funny, but in this world, NOT so funny.
Shahriar, what thermal imager do you use?
It is a Flir E8.
Thanks, it really makes me want to buy one. I've been looking at the E8 for quite a while, good resolution.
Typo in the video title: "AD/DC power source".
Fixed! Thanks.
Did you sell from your instrument collection. That's why I can get in used price.
👍👍👍💖👍👍👍
What xray machine are you using ?
It’s a Faxitron MX-20.
What high voltage differential probe is that ? In the video it says "fully isolated", but the ones I know are not isolated. They have high impedance to ground ( like severa MOhms ) but they are not galvanically isolated.
I wish I could become your student... 🙂
Never expected to see a commercial instrument from a reputable brand with a universal plug of dead (A European two plug power lead fits diagonally across live and earth with the pins still exposed during contact)
"professional use only"
you'd have to be blind and stupid to do that. Anyone who uses one of these units knows which pins are which.
Do you have any idea where to obtain the QL3004-0PFN100C FPGA placed on the control board, or a replacement board? The IC apparently has to be programmed so buying one from a random source is not an option.
We would never have another GW-Instek instrument of any kind after our past experiences with them. Their equipment is so very unreliable, going wrong at some point is the normal for this make. It's totally pot luck as to whether what you have from them will last or not :(
he has thermal camera but uses bare hand to check if the IC hot
I had to find out which IC was the hot one! Since the exact location of the IC is sometime hard to judge from the thermal image alone.
Why only 88.6K subscribers?
The topics covered are fairly advanced (most of the time). That inherently limits the level of interest in the channel.
@@Thesignalpath Okay, I understand that.
Bargain!
This a weird one.
Can the Xray do tomography?
The PSU seems like a clumsy design. I would have pursued a single board solution.
A complex PSU like this wouldn't fit on a single board. Power components like inductors, transformers and IGBTs take a lot of space.
@@simontay4851 of course it can fit. 5A programmable AC. That device is huge, a single board that size could fit 10 of them. Google CE+T little box challenge.
Nope.
It was the caps 2200uf x3 and 1000uf like on all the gw Intek programmable supplies
aqib2000 , Really? More on this would surely be a plus here. It makes more sense, also.
@@BruceNitroxpro the programmable 5a 30v power supplies GW intek and ISOTECH they all have this issuer
I didnt see the bulb powered on and emitting light so I guess its all smoke and mirrors 😉
I think the smoke part already happened before the cover got removed.
0:21 Socket not plug lol... Any conclusion as to why those op amps failed? or did I miss that.
expensive test gear and even more expensive test gear to fix it :)
Thanks, great debug video. Those 3 parts were 90C. And you knew something was drawing a lot of current. A thermal camera is great, but a wet finger or a $20 IR thermometer would find the problem parts pretty quick. Did you say what the parts were? And any theory about why they croaked? Design stress, excess input voltage or output current? 5V op-amps on +/- 5V? Weird load fault? A stray screwdriver? Counterfeit op-amps? Mystery continues...
This could have been caused by the failing voltage regulators. We don’t know how they ‘start-up’. Maybe there were voltage spikes, etc.
Thanks, I agree. I repair a fair amount of stuff that turns out to be bad 78xx or 79xx regulators. Most electronics has a cushy life: regulated supplies, no real heat. It's the regulators that get hot and have to deal with voltage surges. What kind of op-amps were they?
Wait, that is a 5800$ power supply?? Jesus
Dan Frederiksen , I think Keysight would say, "Cheap at half our price!"
@@liam3284 , Thankfully, I'm not in the Market for one... LOL NOT $13,000 + for sure.
@@liam3284 5amps, h bridge, it could probably be done for 100$ but then you can adjust the price depending on market size. Off the top of my head I would think you'd want to combine it with DC supply functionality so you don't have to have multiple product lines. Bigger market. You can have various complex software functionality but that's software, no BOM. CPUs are powerful while costing nada.
It's a glorified A/B audio amplifier attached to a waveform generator, cool.
No, there is a lot more going on.
@@Thesignalpath I'm sure there is as a high-end piece of test gear, but I couldn't help but remember using a powerful rackmount A/B power amp to get a clean 50hz AC using just a sig-gen. Most good amps are DC coupled and will happily amplify DC too if fed and blocking protections bypassed. I remember it had some +/- 180VDC rail config and I couldn't lift it myself. Of course all of this can easily be done in some type of class-D config at 1/20th the size nowadays.
Did you expect to find vacuum tubes? 807s? inside it??? All this running a 5 watt lamp!
You did excellent fancy repair using all these instruments but I may say you are TOOOOO MUCH sensitive to the aging issue and no need for that replacement ....