PC powers on but nothing happens

TheXylis

Reputable
Jan 10, 2016
4
0
4,510
Hey,

The past 4 months my PC was constantly restarting, powering off, and sometimes bluescreening, at first I thought it was just an overheating problem because with speedfan on I noticed my temps sometimes getting up to 100°c so i cleaned it out got rid of all the dust, and for a couple weeks my PC was working fine, no interruptions but then it started happening again, until last week it bluescreened (I don't remember the error code and was too frustrated to record it at the time) and didn't turn back on.

Now my PC powers on but nothing happens, the fans turn on the lights turn on, keyboard and mouse DON'T get power, it doesn't let me turn off the PC from the power button I have to switch it off on the PSU. I've tried taking out the RAM but theres no beeping when I turn it on so it i'm assuming it doesn't get to POST.

What I've tried to do:
Removing the ram and booting it up - no results
Removing the cmos battery for 60 seconds and reseating it - no results
Checking all the connections to make sure nothing got lose - no results
The paper clip trick for my PSU - PSU fan did spin

I can't remove my graphics card because my motherboard doesn't have onboard graphics, I've tried unplugging unnecessary components like the CD drives and lights.

PC Specs:
MB: Gigabyte 990fxa - UD3 - Rev 1
CPU: AMD FX-9370 8 Core Black edition (not overclocked)
CPU Cooler: Corsair Hydro Series H55
GPU: XFX Radeon R9 280x (nto overclocked
RAM: 4x Kingston DDR3 ValueRAM 4GB
PSU: Cougar CMX850 850W
HDD: Western Digital WD Black 1TB
Case: NZXT Switch 810

The CPU, GPU, and PSU are 1.5 years old
The harddrive and RAM are about 4 years old
And the motherboard is 5 years old

Anyone have any ideas? I have an assumption that it's the motherboard but I want to be 100% sure that it is before I go spending $150+ on a new one to find out it was the wrong thing to replace.

Thanks in advance :)
 


I know that the fan is running on the PSU but i don't have a multimeter to check or anything [strike]i can think of to do the 24pin green & black pin power test [/strike]

just did paper clip test and the fan of the psu fan turns on
 
The other day someone brought in a system that was doing something similar. It powered on, all the fans kicked in... but no post(no beep codes either). Tried re-seating all components & testing with various components connected/disconnected. I also connected the psu to a tester and it "seemed" ok. I was about to say it's the motherboard, but decided to try another psu for the hell of it. The system then turned on, posted & went to Windows.
If you don't have another psu on hand, just pick one up from a local shop(if anything, at least Best Buy will have them). You'll be able to return it regardless.
 
Update: I tried a different graphics card in the same PCIe slot, same results. it powered on, fans turned on but no signal on my monitor and no post. I tried that graphics card in a different PCIe slot it powered on etc no post, but weirdly enough it let me turn off my PC from the power button, wat?