Seasonic dead after wrong SATA power cable

[ViktorMS]

Hey I am wondering if anyone has tips to repair a completely dead Seasonic SGX 650.

I plugged in a Thermaltake modular cable by accident and the PSU died. Everything else survived.

The first image (with molex pinouts) is the Seasonic PSU. The second one is the faulty Tt cable.

I measured the resistance of 12V 5V 3V3 and they keep rising until I get an OL reading.

Any tips?

Thanks.

[Per Hansson]

Do you have any 5VSB on the 24pin molex connector?
If not have you checked the basics like the fuse?

[ViktorMS]

I checked the main 240V fuse and it is not blown.

I jump started the PSU and get 0V on 5VSB and everything else, 12V=0V, 5V=0V and 3V3=0V.

[CapLeaker]

I did the same thing and I made a thread about it. In my case it blew the protection diodes in the HDD. It shut the psu down instantly. Anyway… with everything unplugged from the PSU, just plug it into power mains, short the green wire to the black wire on the molex connector and it should fire up. Those things have over current and over voltage protection to save the PSU and prevent a major event. So depending on what you had plugged into the wrong cable, it can stop the computer from working.

https://www.badcaps.net/forum/showthread.php?t=58320

[Per Hansson]

Originally Posted by ViktorMS

I checked the main 240V fuse and it is not blown.

I jump started the PSU and get 0V on 5VSB and everything else, 12V=0V, 5V=0V and 3V3=0V.

Ok, if you do not even have 5v standby working you will have to start from the beginning: measure the voltage on the big main filter capacitor.
It should be around 325v DC with 230v AC input.
If you have a "shaver socket" or something like that providing low current 120VAC that is safer to use, then the voltage should be around 170VDC.

[CapLeaker]

See if PSon voltage is present between the green wire and a black wire. Measure it with your DMM, you should have something like 2.5V there.