PC suddenly turned off, now won't power back on again.

[drarkayl]

I was working all day on the PC, it was on for about 10 hours, then I take a 2 min break and come back and my PC is off. I hit the power switch and it won't turn on again. Just the motherboard led keeps blinking. No fans spin, even the PSU fans do not spin.
This PC has been running without any issues for about 9 months and now this suddenly happens. I cannot figure out what the issue is.

The specs are:
i7-7700k
Asrock z270 killer ski
GTX 1080
16gb corsair vengeance
Evga g3 650w PSU

So far I think my PSU is fine since I tried it my old PC and atleast it boots up.

I tried to use another PSU and still ended up with a dead PC not turning on.

Please help me figure out what can cause this.

Thanks

 

[panathas]

Was the CPU overclocked? Also you didn't mention anything about your GPU. From what you describe your issue is probably motherboard/CPU or GPU (if you have one) related. In cases when you are unable to power on your system you are usually dealing with a lot of variables but in your case you also had an unexpected shutdown and since your PSU seems to be fine, you should turn your attention to the motherboard. So you should:

1)Try to clear the CMOS.
2)Disconnect everything (USB devices, SSD and hard/optical drives, PCIe devices, GPU, 2nd RAM stick) and try to boot only with one RAM stick. If it doesn't work try using all 4 RAM slots. If it still doesn't work do the same with the 2nd RAM stick.

If you still are unable to boot then your mobo is probably bad. One last thing you could do before RMAing it, is to try re-seating the CPU into the socket. Keep in mind that there is still a small chance that you may have a fried CPU but on order to get in that situation you should already have a bad/fried motherboard. Also there is no way to troubleshoot a bad CPU unless you are able to find another one for your specific mobo which isn't so easy.

 

[drarkayl]

No there was no over clock on the CPU.
The GPU is a GTX 1080.
My CPU was pretty stable, never had any temp issues etc. Infact this is the only real issue I had since I built this PC.

The sudden shutdown is the confusing part. I have tried plugging only the 24 pin and 8 pin power connectors, I still get the same issue. Just a blinking led light. No fan movement.

 

[panathas]

OK. Have you tried to clear the CMOS? Try to remove the GPU and boot the PC. Usually a sudden shut down happens in hardware failures. You need to find the specific component that has failed.

 

[drarkayl]

I removed the GPU and every other connection. Just kept the power cables attached, still the same issue. No response .
Whenever the motherboard led blinks I can hear a slight him from the PSU. That's all that happens.

This is exactly what's happening : https://youtu.be/g_iQ8PUlNKI

 

[panathas]

Since you tried another PSU and nothing happened, it's safe to assume that your motherboard is probably dead and you should RMA it. There is still a chance though that you may have a dead CPU but there is no way to troubleshot that without another Kaby Lake CPU and even that is dangerous on a possibly dead/fried motherboard. So return the mobo and hope that your CPU will work with the new board. One last thing before sending it back (if you haven't already tried those) is to try clearing the CMOS and use the 2nd PSU on your system with everything else disconnected.

 

[drarkayl]

I have reset the CMOS a couple of times but it produced the same results. I have never tampered with the bios ever since I built this PC so i don't know what can suddenly happen.

I don't know if this means anything but my regular power supply gives off a slow white led blink while the older psu gives of a rapid orange/red led blink.

I will try taking apart this Pc again, reseat the CPU and build it from scratch. I'll let you know what happens.

 

[drarkayl]

ok I built this PC from scratch again. Re seated the cpu, connected only the power cables, cleared CMOS. Still getting the same results.

No response from the CPU except a slow white LED blink with current PSU and a rapid red LED with the old PSU.

Should i RMA the board? or should i try a new cmos battery? i have never replaced cmos batteries before, are there specific ones for different boards?

 

[panathas]

RMA the board. A dead CMOS battery doesn't prevent a PC from booting up properly. A dead CMOS battery will loose the time and various BIOS settings each time the system turns off. Generally a dead CMOS battery isn't a serious issue, just a nonsense.

Almost all modern motherboards use standard CR2032 coin cells as CMOS batteries nowdays.

 

[drarkayl]

Yeah I'm gonna RMA the board now, will update after I get the replacement.

 

[drarkayl]

After a long wait due to shipping delays, I finally got the replacement. Everything seems fine now. Thanks for all the help.