Bitcoin Forum

My antminer T15 stop working, i already check all boards and the PSU and found no problems at all, it just don't power up.

I remove all boards and leave only the PSU and the control board, same problem, no power up.

I test the control board with other PSU (APW3+) and is working perfect.

I open ther PSU, nothing burn, zero smell (i don't have the cov19 ok, hehe), everthing looks fine, i test the primary protections (varistors, thermistors, fuse, etc.) and evething looks fine, anyone have schematics? or any idea what happens with my PSU? it's the only one i have, is kinda sad after my T17 burn.

I still need check other components like a relay i found in the primary, i guess is part of the protection, is hard to check anything in the primary, is all glued, weird part is that the secundary have no glue.

It's a APW8.

It's almost impossible to fix PSUs from Bitmain unless it's an obvious easy fix, I am not an expert in dealing with all the PSU components but I took a few dead PSU to a friend who knows all about this stuff, and the conclusion I came up with (based on his thoughts) the way these PSUs were built is merely for one-time use, fixing them will consume more time and effort than what they actually worth, unless of course, you have all the skills, spare parts and nothing else to do that makes you money,  in my friend's case he apparently could make a lot of money fixing other things that aren't glued and have no pinouts, so he nicely asked me not to waste his time.  :'(

With that being said, it's worth saying that most PSUs that stopped working for me simply needed a fan replacement, did you confirm that two fans spin just fine? I know thierry4wd (https://bitcointalk.org/index.php?action=profile;u=1656984) plays quite a bit with his PSUs, I hope he would chime in for more thoughts.

PSU failures are typically caused by either a failure in the fans (supply is smart enough to see the fan not spinning or shuts down quickly as the rail overheats), a blown fuse in the input/primary side (happens),  or failures in the high-side FETs on the output rail. When one FET goes (they normally put a number of them in parallel and fire together or in an N phase sequence) it pretty much shuts down the whole supply.

If you're technical, grab a meter and check the resistance of the power supply output leads with the supply off and completely disconnected from the three hashing boards. If it's zero then you have a FET short.

Finding the shorted FET isn't too hard, but you do have to desolder then from the board and check each one. Sometimes a thermal camera can catch it but usually the supply crowbars too quickly. Unless the FET has exploded but a lot of times this doesn't happen. And here is where you find that the cost of paying someone to do this is probably greater than the cost of the supply and might not make sense with the current value of bitcoin, difficulty, etc.

Bitmain knows this, and IMO some of the components they use tend to be a bit "on the edge". Makes sense if the goal is to have the miner survive the warranty period and not much more. Thus as the previous poster pointed out the boards/units are not designed to be fixed easily and are truly "limited use".

Take the example of an old school incandescent light bulb. make it with 1000 hour life you have an endless demand for new ones.

So if have your area constantly lit up and that is very important you must have a few spare lightbulbs. Who cares light bulbs are cheap.

In mining the new gear has constant use and built in psu's

If you buy 5 s17 pro's or more you should make sure to have a spare psu for when the light bulb burns out.
If you only have 1 t17 or 1 s17 or 1 t15 or 1 t17 it is hard to justify having a spare psu.

At op I may have a source for a spare psu if you are USA based. I have a guy in North Carolina.

He has been great with whatsminer m20s parts and I know he has Bitmain repair parts.

https://hmtech.co/

from here

https://bitcointalk.org/index.php?topic=5217069.msg53660629#msg53660629

he has supplied 2 p21 psus to me. and both of my m20s now work.

he also got steamtyme the op of that thread fixed up.

try him.