No power to pc, replace PS, mobo, case

Wigglesdabum

Honorable
Dec 7, 2012
2
0
10,510
I was downloading a game one day and my PC just randomly died. No power, no lights, no fans, nothing. And thus the beginning of a long journey. I replaced the power supply which did nothing, even the power supply fan wont spin( i did test with a paper clip and when its by itself it does run). Then I replaced the mother board. Still nothing not even a light or any noises. Then i replaced the case thinking maybe it as an issue with the button but still no. I tried using the power button on the mobo as well. I am at the end of my rope here. I cant think of anything else other than maybe the CPU being dead. But I feel like I would still get some fans or a light or something. Can anyone please help me with this? I would greatly appreciate it!
 

weaselman

Honorable
Oct 27, 2012
1,146
0
11,360
It may be best to take the board out of the new case, once you have it out make sure there are no extra stand off`s where there should not be one, as a short on the back plate will cause the board and the power supply not to work.
Do a bread board test,(lay just the board on a table ect.) place the Mobo on some card or none conductive surface.
It will be more easy to work with. Start with just the cpu, and one stick of memory, then connect the PSU to all of the points of the board where power is needed dont forget to plug in the 6-8 pin for the Cpu next to the socket. see if it runs. If you have no joy it is likely the old PSU may of taken a few things with it when it stopped working. Cheap PSU`s have been known to take out ram when they go and the Cpu.
 
SEE: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

With the possibilities you have, A PSU tester might come in handy
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&N=100006519&isNodeId=1&Description=Power+supply+tester

The PSU tester, if it indicates a Bad PSU, then PSU is bad. If it shows good it does not always mean it is good. The PSU tester does NOT provide a High enough load to truely test it.

There are two sets of pins that can be jumpered.
1) The pins for Power on. Which basically checks the case switch and a circuit on the MB. No problem doing.
2) the "I'm OK" pins. Basically when the PSU powers on, if it does NOT recieve the I'm OK signal with in XXX milisec the PSU will shot off. This would indicate a MB/CPU/GPU/Ram Problem. Normally you will see a twitch of the CPU fan as it see the +12V which is almost immediatly removed.
NO twitch, then remove GPU, retry power on, still nothing remove ram and retry. Still No twitch then MB or CPU, IE a short that is NOT waiting for the 100 millisec to turn PSU off.
I'm not a lover of shorting this out as it can lead to a "smoke test" - But then again the smoke may tell you where the problem is, but then again it just may agrevate the problem.