Burned out PSU Corsiar HX1200 and NZXT C850, connected to wrong Molex/Sata cable from EVGA.

[coinwizx]

Hi,
Anybody has experience repair PSU burned out due to connect to EVGA molex/sata cables. I know the cable is not compatible (i got them mixed up), but I though i can connect it and use a PSU tested to find out which is the wrong sata/molex cables. As soo as I pluged in the powered molex cable to the PSU tester, the power supply short out, and will not turn on anymore. After the incident, the PSUs (both HX1200 and C850) try to power on and shut itself off immediately. The ATX PSU tester survice the short circult, still working perfectly. Anybody know if it's an easy fix or know which parts need replaced? Possible just an internal fuse burned? Thank for helping.

[CapLeaker]

Usually the PSU survives, but the HDD / SSD etc not. Done the same thing before. I made a thread about it 9 years or so ago here on badcaps. Oh! You used the wrong cable on the ATX tester? Hmm… I think it’s either the 5V or the 12V rail that’s a goner.

First off make sure nothing is connected to the power supply, jump the green (PSon) wire to black (GND), then plug in the power supply to power mains and see what happens. Measure the orange, red and yellow wires against the black (GND). Just one wire from those colours.

If it doesn’t turn on, the supervisor IC detected a fault on one or more power rails and that isn’t just a fuse problem rather a diode or something else.

I’d suggest you making 2 threads, one for each PSU. Open it up and upload some nice straight shot high resolution pictures, so we can see something.

[Agent24]

The wrong HDD cable itself shouldn't damage the power supply, but if Ground and some power rails were swapped in the cable pinout...

What you have normally on a HDD cable is 12v and 5v plus ground going into the PSU tester, and two of those pins are ground, and assumed to be connected together.

But if the cables that were meant to be ground, were actually 12v and 5v, well now you got 12v rail and 5v rail shorted together at the PSU tester on what is supposed to be a ground connection, and quite possibly the power supply has back-fed 12v into its own 5v (or even 3.3v rail if it's a SATA connector) and something has been damaged on the 5v or 3.3v rails, either the monitoring circuitry or if the PSU uses DC-DC converters for the 5v and 3.3v, maybe that instead or as well.

That's going to be a fun one.

You're going to need to start posting photos, and find out which rail(s) aren't working anymore

[kotel studios]

Another cause for your issue of them not wanting to power on, is that the OCP/UVP kicked in and needs to be reset. Usually it's enough to cut mains power to the PSU and wait a few seconds before powering it on again, but I suspect you have waited out at least 30 sec before you turned them on again...

[coinwizx]

David analysis is right. The 12v back feeded to the psu own 5v damaged something inernally, now the psu try to turn on, but internal monitor circuilt shut itslf down when try to power on. I got no reading on 5v and 3v, but 12v has split second of power, then shut off itself as i turn the power on. I saw the fan span for a few seconds The power supply then will not turn on again until it reset a few minutes later. So, the question is if this possible an easy fix? if yes, i will open them up...if not, then i may RMA them..

[coinwizx]

Hi,
Anybody has experience repair PSU burned out due to connect to EVGA molex/sata cables. I know the cable is not compatible (i got them mixed up), but I though i can connect it and use a PSU tested to find out which is the wrong sata/molex cables. As soo as I pluged in the powered molex cable to the PSU tester, the power supply short out, and will not turn on anymore. After the incident, the PSUs (both HX1200 and C850) try to power on and shut itself off immediately. The ATX PSU tester survice the short circult, still working perfectly. Anybody know if it's an easy fix or know which parts need replaced? Possible just an internal fuse burned? Thank for helping.

******
David analysis is right. The 12v back feeded to the psu own 5v damaged something inernally, now the psu try to turn on, but internal monitor circuilt shut itslf down when try to power on. I got no reading on 5v and 3v, but 12v has split second of power, then shut off itself as i turn the power on. I saw the fan span for a few seconds The power supply then will not turn on again until it reset a few minutes later. So, the question is if this possible an easy fix? if yes, i will open them up...if not, then i may RMA them..

[Agent24]

It may be easy to fix, it may be not.
You won't know until you open it.

[stj]

and post pictures