HELP-pc turns on then off instantly

[user157]

So when I turn my pc on it turns off almost instantly and turns back on and off in a cycle, if I turn it on via power supply and then wait a few minutes and turn it on it will run but with no signal and with the code '00' on my (asus) motherboard, aswell as the cpu led being lit red. I'm a bit lost here as the psu fan spins, I've re-plugged all cables,repeated ram in multiple slots and even reset cmos and the issues still occur,the pc is old so It could be to do with that but I dont really see any reason why my certain problem would happen.
SPECS:
i5 4690k
Gtx 980
2x8gb hyperx savage ddr3
Asus maximus ranger 7 mobo
A corsair psu not sure which one
Corsair h80i v2 watercooling

 

[GerKNG]

00 means no CPU.
either your CPU is dead or you Mobo has some significant issue.

 

[P4-630]

If you're facing issues with booting up and encountering Q-CODE 00, it indicates an abnormality in the CPU during the POST process.

I'd try another PSU first.

 

[user157]

00 means no CPU.
either your CPU is dead or you Mobo has some significant issue.

Can a cpu really just 'die' though? It was working fine before as far as I'm aware

 

[P4-630]

Can a cpu really just 'die' though? It was working fine before as far as I'm aware

Could have been caused by a failing PSU is my guess.....

 

[user157]

Could have been caused by a failing PSU is my guess.....

The fan spins though... or am I wrong in thinking that that means it works?

 

[GerKNG]

Can a cpu really just 'die' though? It was working fine before as far as I'm aware

rare but not impossible.
could be anything related to the CPU incl. the Mobo.
if a cmos reset, fresh battery and one ram stick just posts "00" it's pretty much over.

 

[P4-630]

rare but not impossible.
could be anything related to the CPU incl. the Mobo.
if a cmos reset, fresh battery and one ram stick just posts "00" it's pretty much over.

Or the old PSU took out some of the hardware?....

 

[user157]

rare but not impossible.
could be anything related to the CPU incl. the Mobo.
if a cmos reset, fresh battery and one ram stick just posts "00" it's pretty much over.

Alr I did think that it was but i js wanted to make sure

 

[P4-630]

Ok, it's a K CPU, might have been OC'd all his life..

 

[GerKNG]

Or the old PSU took out some of the hardware?....

Post Code, fans spinning and an attempt to post sounds odd if the PSU would be the culprit. if it would fry something or causing a short or having other massive problems it should refuse to power on at all.
hard to diagnose out of a few lines of text.

 

[Bill_Bright]

fans spinning and an attempt to post sounds odd if the PSU would be the culprit.

One must remember that a PSU supplies 3 separate voltages to various points on the motherboard and throughout the case. That's +12VDC, +5VDC and +3.3VDC. Fans could spin up because they are receiving +12V, but the +5 or +3.3V might be missing, or out of tolerance.

Since EVERYTHING inside the computer case depends on good, clean, stable power, you need to verify you are providing it before moving on to other possibilities. The best way to do that is to swap in another known good PSU and see what happens.