I have been having some strange issues with my PC. Twice a day, the computer will just shutdown – no warning, just an instant black screen power off. Now, all the lights and such in the PC are on, graphic peripheral power is green etc, however pressing the power button just does nothing. After a few hours (sometimes turning off at the wall works) it will magically start working again, no issues in runtime (the bios has reset, however) and well. yea.
In addition to this, it will also start randomly powering on. Just randomly, in the middle of the night, will just boot itself up.
I first thought power supply, pulled out my multimeter and checked all of the 24-pin outputs, all check out fine (with the largest deviation is 0.1V). I checked the PS when the PC was turning on fine and when it was not, pretty much the same values.
So, probably not the PSU. So, unplugged everything, RAM – GPU – HDD/SSDs, still not turning on (and unfortunately I can't unplug the CPU simply because it won't turn on anyway (or will it?) ). I thought maybe thermal issues, but it's' running cold. Even did a bare hand test, flat cold (plus, it would cool down after a few hours, however sometimes it doesn't turn on).
I even went so far to test the waveform of our power to maybe see if that could have made a difference (I was getting desperate), but it's perfect ~50Hz sinewave.
So I'm thinking either Motherboard or CPU. I just want to get a second-hand opinion on this. I was planning on getting a new MB and a CPU to go with it anyhow, but I don't want to go purchase it then realising a) the issues still happening and b) I'll have no left over cash to buy the 'fix'.
I've done a bit of googling around and most people say it's probably the PSU, but the pin values are perfect so I can't imagine it's that. Plus, the PSU it's too old at around ~3 years.
Just to clarify, when I say not turning on, I mean not turning on. No fan spin-ups, no nothing. The only sign of life are the lights on the GPU that glow if it's receiving power or not.
My specs are below (probably not important but still): - Nvidia GeForce GTX 780 - Intel 4440 CPU - Thermaltake Toughpower 750W - Asus B85M-E Motherboard
I was planning to try and boot into Linux the next time it starts working to see if the issue will happen in Linux (could be some gnarly virus causing sustained processor interrupts, maybe.. as I said – getting desperate)
Anyway, any help or opinions would be appreciated!