Weird maybe PSU issue frying vid cards

[psk94]

Running a Seasonic G series from 2012 (550w gold rated) on an Asus p8z77, my Nvidia 1070 vid card randomly died while gaming, PC shut off and PC won't boot if power cable is plugged into it... figured it was a 12v short and moved on (tried it in other slot and different PC, no change). Onboard Intel graphics work 100% no issue, everything else in PC runs fine forever. Got an ancient lightly used 5750 lightly to test, plugged it into same PC, worked for 2 hours and then random black screen no signal permanently after that, including if I move it to another PC , so it's fried somehow (temps were fine 65C topped during light gaming, and was actually idle on desktop when it happened).

Now what is more likely; mobo pci-express slot damaged ruining the cards somehow, or the Seasonic PSU graphics card rails/plugs spiking voltage or doing something to destroy these cards? I mean it's possible it was just the cards, but seems unlikely at this point.

 

[psk94]

You would think there would be other problems if it was the power supply, but I'm not an expert. First card fried a month ago, been using onboard graphics with that PSU and gaming on it with 0 issues, no quirks or funny business. Just trying to hold out until Arrowlake launches in fall to do a new build finally. I mean I GUESS I could get a new seasonic PSU ahead of time, as one of the few parts you can test properly before an entire new build... then if it is the mobo and fries a new card lmao, don't think I want to risk that unless the card is under $50 again.

 

[psk94]

Have you monitored the voltage rails using something like hwinfo or better yet a physical multimeter?

Don't have a multimeter and didn't think of doing that in software... I assume you mean this (pic), looks normal with monitoring turned on never budging. That's with onboard graphics only, have been gaming on it to stress it without issue so far, but obviously not hooked up to gpu cables.