Question Can anyone tell me if the following is a psu problem?

Oct 5, 2019
Hi, last week my computer stopped booting but the led power logo on the motherboard was lit but nothing was happening. I should say I had just changed the cpu and before that the pc was fine. I just bought another psu from ebay and it's doing the same.
The psu was a corsair ax750 and new is hx650. When doing the paperclip test both start to spin then stop. I'm wondering if the fan only stays on for longerwhen the psu gets hot and it hasn't actually been the psu! I had the Ax750 from new in 2014 and never had a problem.
Also the cpu I installed was full of crap and got crap on the pins. I only saw it after looking at both under a lens and managed to get it off the pins without damaging any.
I've also tried with the old cpu with the same result.

Oh yeh I did drop the graphics card onto the motherboard from about an inch in height.

I've been building computers for years and did it as a job but this is doing my head in especially after spend my food money on a psu so I could get my uni assignment in and it doesn't even work! The full computer nearly went out the window early but I butted the wall and pulled some pubes out instead... I'm receding so avoided the hair!

It's a Asus z87 pro and i7 4790k it's not a bios problem because it's the same model of cpu I built the computer with. There's no power going into the motherboard, I don't know if both psus are faulty or it's the motherboard and that is causing damage to the psu. After fitting the replacement as soon as it wouldn't power on I unplugged everything so I doubt it was damaged by the motherboard. The guy I bought it from says it came from a working computer.

Help anyone please!


Update your post to include full system hardware specs and OS.

When you changed the CPU what thermal paste did you use?

Have you tried a new CMOS battery?

Use that lens and a bright flashlight to closely examine the motherboard in the area hit by the graphics card. Look for signs of damage; browned/blackened areas, broken/bent electronics, scratched traces, etc..
Oct 5, 2019
Specs, i7 4790k, Asus z87 Pro, ax750 then hx650. 4x4gb avexir core 1600mhz. Ive tried taking each stick out separately. 500gb Samsung evo 860 ssd. 3x1tb hdd. Evga Gtx 980 ftw. Custom watercooling xspc, alphacool. OS win7.
There's no damage on the motherboard. Thermal paste is gelid gc extreme also tried phobya hegrease.
After taking everything apart a few times and back together the system started to crank up but motherboard code stayed 00 and it conked out after a couple of seconds and continued to do the same.

Yes I did try a new cmos.

There was stuff stuck to the pins after installing the new cpu but I used the tip of a zip tie and got rid of it without bending any pins. I can see a tiny bit on the bottom between the pins but not on any pins. There was a thin coat of something on the underside of the cpu mixed with tiny dust granules.
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