Question PC turns on and immediately turns off.

[TheNexus]

Specs: i7 8700, rtx 2070 super, seasonic Focus 80+ Gold 550W. So this morning my pc was working just fine. Turned it off, went outside, came back and when I tried to turn it on it didn't do anything for like 2 seconds then it turned on and immediately turned off again. I took a look inside and found out that the a red LED labeled CPU was also flashing for that brief moment the pc was on. Firstly I removed my cooler and the cpu. Tried turning it on without a cpu and it did the same thing. Changed the thermal paste as it wasn't changed for a while and put everything back. Tried again and same thing. I removed my gpu and tried turning it on again. This time it was turning on and off endlessly, on for like 1-2 seconds and off for like 1-2 seconds. Tried to short the green wire and the ground wire on the 24 pin connector to see if the psu is dead. It was not it was working fine. The psu fan was spinning. I have two sticks of ram (2x8GB) an i tried using just one. Switched it around, tried all logical positions. Same thing. Any suggestions on what I could do?

 

[Ralston18]

Is the computer clean and clear of dust and debris? If not clean accordingly.

Double check that cards, cables, RAM, and jumpers are fully and firmly in place. Do so by touch and gentle pressure.

Failing that:

PSU is still suspect. The "shorting" test is very basic.

How old is the PSU and how has it been used: heavy gaming, graphics work, bit-mining.....?

Was the PSU new, used, refurbished?

You can do more PSU testing if you have a multi-meter and know how to use it. Or have a family member or friend who does.

Reference:

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

Still not a full test as the PSU is not under load. However if one or more voltages are out of spec then the PSU may indeed be the culprit.

 

[TheNexus]

I bought the system 2 years ago. Everything was bought brand new. I had it built by someone else. It was used primarily for gaming. It is pretty dusty so I'll try and clean it a bit more. Also regarding cables, ram etc I found that all of them are into place as far as I could tell. Is there a possibility the cpu is the problem? What does the change of behaviour when removing the gpu mean?

 

[TheNexus]

Update: I removed my gpu and m2 ssd. It started off with turning on and off and all the red leds flashing (labeled cpu/dram and vga/boot, pic:

https://imgur.com/a/q69hJKH

View: http://imgur.com/a/q69hJKH
) after a while it stayed on and the leds stopped flashing and it worked. Then I tried to put in my gpu because I didnt have the necessary cables to plug my monitor in my integrated gpu but when I tried to boot it with my gpu in and no ssd it did the same thing as the title. On and immediately off. Tried again with both gpu and ssd removed and it started the on and off loop. Tired it again and it did the thing that I explained previously and the pc remained on. Whats the broken part here?

 

[TheNexus]

Update 2: I found out what the issue is. It was the GPU. If you are reading this and having the same problem try booting your pc without your gpu and see if it works with one that you are sure isn't busted. Fortunately I could sent it back and have it replaced/fixed.