In repairing avionics equipment. To find a short we sometimes put the PCB in a deep freezer until the card frost over. Then when we apply power(current limited) the short thaws first. You can take a marker and mark the bad path to the short. We let the board completely dry before further troubleshooting.
You have great determination resolving the short that way, we fix a large number of PCB's with shorts (often shorted ceramic caps), we have thermal camera's but often find voltage/current injection works better for hard shorts where little heat is generated. To diagnose a 5V short, set a lab PSU to 5V 100mA (you can increase the current but you risk damaging traces etc) then inject it into the PCB 5V rail close to the PSU input, then simply set your multimeter to mV and start probing the 5V capacitors (or other components on the 5V rail), you will notice the mV decrease as you get closer to the short, the lowest reading (usually close to 0mV) should identify the issue/component, you can also inject the 5V 100mA across the 5V rail away from the PSU input if you suspect an issue around that area.
Instead of waiting 30 seconds watching a black screen. a hint is to add a powerled.. as the powerled goes to full brightness after 1 sec if code is running..
Nice fix! Lucky the rest of the machine wasn't damaged due to the short! A thermal imaging camera would probably picked up the heating of the coil even if it's a few tenths of a degree you would've picked up on it. Yes it costs money but it can save you a lot of time fault finding, and it's great for finding cold spots during winter in your house, insulating those and avoiding cold bridges with dampness and fungus etc can save you a lot of headaches. I've also used it on my car to spot a weakness in the exhaust pipe, a brake jaw being stuck etc. that the car repair men didn't pick up on. Oh and buy low melt solder, it'll help not lifting pads as it lowers the melting temperature even more than leaded solder. I've soldered and removed 44 pin PLCCs more than 10 times from the same set of pads and there's no damage. I only needed 10mm of that stuff to remove the IC.
Well done my friend. I had a proud laugh at your misfortune but was still impressed with how you went about it. Super impressed with what you had planned with the contact cleaner.
Another great video, Glenn! Back when I was QA Mgr for T.I., we were fortunate to have both the thermal image camera & a device that allowed us to check surface mount components while in the board. I learned to start from the voltage in, the IC pins, sockets, a full board wash, and de-oxit sockets later seemed to help cut our refurb time down considerably.
@@coolvideos8864 more than happy to look at it but at this stage it'll be after Christmas. Are you sure its not just the ROM in it? Some 600s shipped with a ROM that doesn't have the IDE support in it, or only supports small drives. Drop me an e-mail casualretrogamer@outlook.com if you want me to look at it.
There is a simpler way to localize the short circuit. Take a sensitive milliohm meter (a modern 10000 count multimeter at the 100 Ohm range will be typically enough) and measure the resistance in various points on the shorted line. The lowest resistance will indicate the culprit.
I tried that with my meter and I have had some luck with it before but on this board it was just 0.04ohms everywhere which is probably the leads themselves. Probably should have shown that in the video!
Cool to see another rev. 1a board; that's what mine is, and it also took out an accelerator connector due to the square edge! I've since chamfered mine as well.
The black screen delay on boot is a 3.1 ROM "feature" it expects a HDD - if you put in an IDE drive or IDE to CF or IDE to SD it will boot quicker (or use 3.0 ROMs)
I notticed that a cap was placed between the 10 uF next to the IDE Header, and the 22 uF behind the RF modulator, so when the two 1000 uF caps returned (?), you chose to leave it.
Thanks for the video. Thermal cameras really are too expensive. I also tried rosin atomizer, but it only leaves mess on the board and is not really useful. Other method which could be worth considering, if you can reduce problem to some smaller area, is using one of those cheap laser thermometers and check one component after another.
I looked at those atomizers but was told they leave a terrible mess which is hard to clean up. I do have one of those digital thermometers and I was thinking about it but not knowing were on the board was shorted it would have taken a long time to find.
Great video, especially chasing the fault. You can still get a deal on thermal kit, it’s only the high resolution cameras that are eye watering expensive 😮 A budget one will do the job most times, but you can also use flux resin with an ioniser to identify thermal stress on components.
I looked at those flux resin things but I was told they make a terrible mess which is hard to clean up and given the size of the 1200s board there would have been a lot of flux fog. I may get some sort of thermal imaging device at some point but few other bits of equipment I want to buy first. Thanks for the tip and glad to hear you enjoyed the video.
I tend to think the original cause of the fault was a bit of solder or a stray capacitor leg ended up in the slot. Just based on the visual inspection and the board having been recapped.
That typically happens more with tantalum caps, they like to exploded when they fail although I suppose with enough current a ceramic could get hot enough to frazzle.
@ddniUK I've been struggling with that one myself. If the psu shorted internally it would only have damaged itself, if its outputs had gone high it could have caused the short but I would have expected it to fry the Amiga. Given the damage at the cpu slot all I can conclude is that the board shorted here but the fact the psu had no over current protection lead to the trace burning through and the damage to the filter.
@@CRG Ya, nothing I see here indicates (to me) that the PSU was a problem. I only have experience with an Electroware PSU for the 64, but I was happy with its build quality and components. The 64 PSU by Electroware uses a quality Mean Well switching power supply inside that has overcurrent protection, if memory serves (from my buying Mean Well components). I would not be surprised if their Amiga PSU also uses a Mean Well switching power supply inside. If interested, I have a video teardown, mod, and rebuild an Electoware PSU - it's called "Electroware C64 PSU heavy-duty mod (30W DC power)" on my channel. (Not posting link to avoid angering the YT comment killer. :) Peace.
@@DrDavesDiversionsI'll take a look, thanks. I've used meanwell PSUs to replace failed Amiga PSU bricks (just swapping out the internals of the PSU case) and as you say they always seem to be well built.
Very same thing happened to my TF1230 - connector pins pushed out of alignment. How you planning on fixing the board? I was told it was going to be too difficult to remove the connector on the board to replace. Cheers! Jim
I don't think you did the current limit setup properly. You should turn current limit to 0, set your voltage, short your leads, then turn the current limit up until you hit the voltage and current you expect. That's the way I do it at least. You're testing for a dead short, and if you want 5v at 100ma, you need to set your meter to 5v 100ma with a dead short (shorting the leads first). If you search up Adamant IT he has a video about voltage injection that talks about this. He's referring to modern computers with CPU's that only take 1 volt, but the theory is the same.
OK, I've paused the video at the beginning, and I've watched enough Lateral podcast highlights that I think I can figure out the reason. Obviously could be the usual capacitor or dodgy logic chip, or it could be a burnt resistor. Maybe a diode? Or perhaps you don't mean a short circuit, maybe someone has short sold it on the stock market? No, that's silly. How about short sold it on a retro forum, like they've borrowed it from someone and sold it at a higher price in the hope of finding one for cheaper and buying that to replace the one they borrowed? Or maybe I should stop trying to turn this into a game show and just watch the video to find out.
Well, it certainly wasn't what I expected, but good on you for persisting and spotting the dodgy coil. By the way, the joke would be "there's a broken ferrite ring on my Wang", or before you found the fault, "I hope my Wang hasn't blown its cap!"
They are all vcc on one side and gnd on the other so all read as shorted while on the board. In hindsight when nothing was getting hot I should have stepped back and checked other things before starting into the ceramics. But it's done now and at least I got it fixed in the end.
I don't script my videos, rather I just talk as I work so yes on occasion I may describe something wrong although I'm sure you knew what I was talking about.
![อยู่คนเดียวกับเขา - ส้ม มารี (Zom Marie) [Official MV]](http://i.ytimg.com/vi/gq1cWAIQDLg/mqdefault.jpg)
In repairing avionics equipment. To find a short we sometimes put the PCB in a deep freezer until the card frost over. Then when we apply power(current limited) the short thaws first. You can take a marker and mark the bad path to the short. We let the board completely dry before further troubleshooting.
You have great determination resolving the short that way, we fix a large number of PCB's with shorts (often shorted ceramic caps), we have thermal camera's but often find voltage/current injection works better for hard shorts where little heat is generated. To diagnose a 5V short, set a lab PSU to 5V 100mA (you can increase the current but you risk damaging traces etc) then inject it into the PCB 5V rail close to the PSU input, then simply set your multimeter to mV and start probing the 5V capacitors (or other components on the 5V rail), you will notice the mV decrease as you get closer to the short, the lowest reading (usually close to 0mV) should identify the issue/component, you can also inject the 5V 100mA across the 5V rail away from the PSU input if you suspect an issue around that area.
Thanks for the tip, I'll try that next time.
@@CRG The thought process and logical thinking towards fixing the problem was far more valuable than the actual fix... Enjoyed very much indeed CRG.
Instead of waiting 30 seconds watching a black screen. a hint is to add a powerled.. as the powerled goes to full brightness after 1 sec if code is running..
Good point, I should make up an led to plug in when I need it. Should probably write a set of diag roms as well!
Nice fix! Lucky the rest of the machine wasn't damaged due to the short!
A thermal imaging camera would probably picked up the heating of the coil even if it's a few tenths of a degree you would've picked up on it. Yes it costs money but it can save you a lot of time fault finding, and it's great for finding cold spots during winter in your house, insulating those and avoiding cold bridges with dampness and fungus etc can save you a lot of headaches. I've also used it on my car to spot a weakness in the exhaust pipe, a brake jaw being stuck etc. that the car repair men didn't pick up on.
Oh and buy low melt solder, it'll help not lifting pads as it lowers the melting temperature even more than leaded solder. I've soldered and removed 44 pin PLCCs more than 10 times from the same set of pads and there's no damage. I only needed 10mm of that stuff to remove the IC.
Well done my friend. I had a proud laugh at your misfortune but was still impressed with how you went about it. Super impressed with what you had planned with the contact cleaner.
that was a helluva wild goose chase until you found the culprit!these amiga boards are something else sometimes..great job glenn!
Thanks, it did send me on a bit of a journey.
Thanks for sharing Commander!
Great troubleshooting work! -Mark.
Thanks 👍
Another great video, Glenn! Back when I was QA Mgr for T.I., we were fortunate to have both the thermal image camera & a device that allowed us to check surface mount components while in the board. I learned to start from the voltage in, the IC pins, sockets, a full board wash, and de-oxit sockets later seemed to help cut our refurb time down considerably.
Sounds interesting. In hindsight I should have started from the voltage in and checked that filter first!
Seriously love your channel mate! Nice video, as always.
Thanks, glad to hear you're enjoying the videos.
@@CRG I have an a600 with non functioning onboard IDE if you fancy a look? Would appreciate it if you could, ok if not
@@coolvideos8864 more than happy to look at it but at this stage it'll be after Christmas. Are you sure its not just the ROM in it? Some 600s shipped with a ROM that doesn't have the IDE support in it, or only supports small drives. Drop me an e-mail casualretrogamer@outlook.com if you want me to look at it.
@@CRG thanks for the reply, I’ll try another ROM tomorrow. I’ll drop you an email. Thanks, Graham
There is a simpler way to localize the short circuit. Take a sensitive milliohm meter (a modern 10000 count multimeter at the 100 Ohm range will be typically enough) and measure the resistance in various points on the shorted line. The lowest resistance will indicate the culprit.
I tried that with my meter and I have had some luck with it before but on this board it was just 0.04ohms everywhere which is probably the leads themselves. Probably should have shown that in the video!
@@CRG Less than 0.01 Ohm difference all over the board? The power lines should be really thick and wide for such a low resistance.
@@CRG You can also feed a high fixed current and measure the voltage drop (this is often called the "4-wire" method).
I started watching your rgb mod for G7000 videos, and now I'm down a CRG sized rabbit hole. Great stuff!
That's a big rabbit 😅. Glad to hear you've been enjoying the videos.
I enjoyed watching your troubleshooting 😊
Thanks, glad to hear you enjoyed it.
Cool to see another rev. 1a board; that's what mine is, and it also took out an accelerator connector due to the square edge! I've since chamfered mine as well.
First time I've had one on the bench, was good fun to work on, even if it did send me on a journey 😅
Wow, great that you fixed it. You win the tenacity award. :)
Thanks, I knew I'd eventually find the shorted part, I just never expected it to be what it was!
Great work finding the short great channel 👍😋
Thanks, glad to hear you're enjoying the channel.
your'e the man. Love your videos.
The black screen delay on boot is a 3.1 ROM "feature" it expects a HDD - if you put in an IDE drive or IDE to CF or IDE to SD it will boot quicker (or use 3.0 ROMs)
I notticed that a cap was placed between the 10 uF next to the IDE Header, and the 22 uF behind the RF modulator, so when the two 1000 uF caps returned (?), you chose to leave it.
IPA on shorted boards has one disadvantage - it's quite flammable as TheCod3er proved in one of his YT videos.
Yeah I was worried about flames but I suppose it would have added some drama 😅
Thanks for the video 😄
Thanks for watching 👍
I’m fairly certain that there are international treaties in place that prohibit the mixing of two-part epoxy directly on your solder mat.
I cleans off easily enough with a little IPA, but yeah I'll use a bit of cardboard next time 😆
By the way, the power trace has burned out BEFORE the filter but not anywhere AFTER it, this can be the clue...
Yeah that's a good point and in hindsight it would have been a heck of a lot easier to just pull the filter and test it to begin with.
Thanks for the video. Thermal cameras really are too expensive. I also tried rosin atomizer, but it only leaves mess on the board and is not really useful. Other method which could be worth considering, if you can reduce problem to some smaller area, is using one of those cheap laser thermometers and check one component after another.
I looked at those atomizers but was told they leave a terrible mess which is hard to clean up. I do have one of those digital thermometers and I was thinking about it but not knowing were on the board was shorted it would have taken a long time to find.
Great video, especially chasing the fault. You can still get a deal on thermal kit, it’s only the high resolution cameras that are eye watering expensive 😮 A budget one will do the job most times, but you can also use flux resin with an ioniser to identify thermal stress on components.
I looked at those flux resin things but I was told they make a terrible mess which is hard to clean up and given the size of the 1200s board there would have been a lot of flux fog. I may get some sort of thermal imaging device at some point but few other bits of equipment I want to buy first. Thanks for the tip and glad to hear you enjoyed the video.
I tend to think the original cause of the fault was a bit of solder or a stray capacitor leg ended up in the slot. Just based on the visual inspection and the board having been recapped.
Possible, the short certainly occurred at the cpu slot but I've nothing to confirm how.
:D It would be VERY late on my list as well!
Lol aways start at the beginning lol. 😢
This happened on my PSOne and two SMD caps blew a chunk out of the board when they blew.
That typically happens more with tantalum caps, they like to exploded when they fail although I suppose with enough current a ceramic could get hot enough to frazzle.
Good video. I hope Honest Gamer has a trusted PSU to use with the repaired board. Did he send you the one he used?
Yes, he has a different psu now but no he didn't send the psu he was using when it went. All he provided was the board.
@@CRG be great to know what the “bad” PSU did.
@ddniUK I've been struggling with that one myself. If the psu shorted internally it would only have damaged itself, if its outputs had gone high it could have caused the short but I would have expected it to fry the Amiga. Given the damage at the cpu slot all I can conclude is that the board shorted here but the fact the psu had no over current protection lead to the trace burning through and the damage to the filter.
@@CRG Ya, nothing I see here indicates (to me) that the PSU was a problem.
I only have experience with an Electroware PSU for the 64, but I was happy with its build quality and components. The 64 PSU by Electroware uses a quality Mean Well switching power supply inside that has overcurrent protection, if memory serves (from my buying Mean Well components). I would not be surprised if their Amiga PSU also uses a Mean Well switching power supply inside.
If interested, I have a video teardown, mod, and rebuild an Electoware PSU - it's called "Electroware C64 PSU heavy-duty mod (30W DC power)" on my channel.
(Not posting link to avoid angering the YT comment killer. :)
Peace.
@@DrDavesDiversionsI'll take a look, thanks. I've used meanwell PSUs to replace failed Amiga PSU bricks (just swapping out the internals of the PSU case) and as you say they always seem to be well built.
Very same thing happened to my TF1230 - connector pins pushed out of alignment. How you planning on fixing the board? I was told it was going to be too difficult to remove the connector on the board to replace. Cheers! Jim
All I can do is try to remove it. The old connector is scrap so I may have to pull the pins out one at a time.
I don't think you did the current limit setup properly. You should turn current limit to 0, set your voltage, short your leads, then turn the current limit up until you hit the voltage and current you expect. That's the way I do it at least. You're testing for a dead short, and if you want 5v at 100ma, you need to set your meter to 5v 100ma with a dead short (shorting the leads first). If you search up Adamant IT he has a video about voltage injection that talks about this. He's referring to modern computers with CPU's that only take 1 volt, but the theory is the same.
I'll take a look thanks, I've not done this before so just had a go as how I thought it should work.
You can rewind choke/transformer
Good point although I had the spare so easier to just use that.
OK, I've paused the video at the beginning, and I've watched enough Lateral podcast highlights that I think I can figure out the reason. Obviously could be the usual capacitor or dodgy logic chip, or it could be a burnt resistor. Maybe a diode? Or perhaps you don't mean a short circuit, maybe someone has short sold it on the stock market? No, that's silly. How about short sold it on a retro forum, like they've borrowed it from someone and sold it at a higher price in the hope of finding one for cheaper and buying that to replace the one they borrowed?
Or maybe I should stop trying to turn this into a game show and just watch the video to find out.
Well, it certainly wasn't what I expected, but good on you for persisting and spotting the dodgy coil.
By the way, the joke would be "there's a broken ferrite ring on my Wang", or before you found the fault, "I hope my Wang hasn't blown its cap!"
A broken ferrite ring on your wang... sounds painful 😂
couls you not just have checked those caps while they were in the board
They are all vcc on one side and gnd on the other so all read as shorted while on the board. In hindsight when nothing was getting hot I should have stepped back and checked other things before starting into the ceramics. But it's done now and at least I got it fixed in the end.
it isn't astually a pin on that connector its a copper trace
He knows what it is dude, stop nitpicking.
I don't script my videos, rather I just talk as I work so yes on occasion I may describe something wrong although I'm sure you knew what I was talking about.