PC doesn't perform POST. Powers on by itself and no display

[abdkidrauhl]

So my Dell Optiplex 780 hanged for a couple of seconds turned off on its own. Restrated by itself. On restart there were 6 short beeps which meant smthing to do with the RAM I guess. So I took the memory stick out wiped it of dust with a towel and some tissues. Put it back again. Everything was supposed to work but when I plugged the power cord the PC turned on automatically, didn't go through POST and no display at all. Tried pulling out my GPU (GT 710) and cleaned it the out of dust. Put it back in. Still the same but this time the PC turned off for a second then on again then off then on with no display. All fans and lights running. Just when I plug the PC in it switches on by itself. I don't get to press the power button as usual. Turns off by itself a couple of times and on again with no display and does't perform POST. I tried resseting the CMOS, reseating the memory stick into a different slot and plugging the GPU out. Still same. Please help. I need to finish a project by this weekend

 

[Tkennedy1993]

Do you happen to have the PSU tester that usually comes with the power supply? If so test the power supply with it. You can also test the PSU using a paper clip please see link below for instructions. If the power supply turns on then it is not your power supply and you could be looking at a CPU issue.

https://solvexp.blogspot.com/2013/08/how-to-test-your-power-supply-without_17.html