1. Will it boot up in safe mode (F8) ??
2. When you opened it to replace the graphics card. Was there any accumulation of dust?? I have seen a machine do this due to dust.
3. How many sticks of ram do you have? If more than one , have you tried to boot off of each one separately, after being reseated??
I'm not saying, it's not the power supply. Just some more things to check.
It's been a few months since I've powered my PC desktop on for various reasons.. Anyway, I tried to turn it on today and it completely powered off before evening starting up.
The first time I turned it on, it abruptly powered off after the Windows logo appeared. I turned it on a second time and went to the BIOS screen, where after a minute or so, it abruptly powered off again.
Something else I've noticed is that the "Building Wiring Fault" indicator on my Back-UPS ES 350 is lit up. Could it be that my PC is just not getting enough juice due to faulty wiring? It's not exactly a new UPS though..
Please and thank you for any help you can offer!