Autamatic turn on when plugged (no boot)

alamatnitotoy

Honorable
Sep 2, 2012
7
0
10,510
hi everyone..,
im a newbie here but hopefully someone can welcome me with an answer..

anyway heres my situation,

like what my topic states, my desktop will automatically powers up but no boot

-system fan spin like in 100% speed
-gpu fan spin
-cpu fan spin
-no monitor signal from onboard or card
-hdd led not lit
-power led is on

and when I press the power botton the system fan speed will slow down but still spin, and still no boot.

things I have done so far:
--purchase another psu to test (gmc 500watts true rated)
-remove the board from the case
(ok so I remove the mobo from the case with all of its component plug.)
after turning on the psu, im surprised that the mobo did not power on so I thought the culprit is the case, I thought it was grounded or something but after a few powercycle, the problem occurs again. so I remove all of the components leaving only the cpu and 24pin plug but still same issue.

my motherboard is gigabyte 880gm-ud2h.
I have already tried all of the troubleshoting I know but I cant seem to isolate the problem.

-also I have tried holding the power button for a couple seconds and sometimes the desktop will boot normally and I was able to use it for 2 days without a problem.

thanks
 

egilbe

Distinguished
Nov 17, 2011
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0
19,460
Only thing I can think of is to take it all apart again and re-assemble it making sure all the connectors are properly seated. I'm never heard of a PC doing what you described so I wouldn't even know where to start. Are you sure the PSU is good and is powerful enough for the system? Take it down to the bare minimum components and see if it boots and add components one at a time and see if it boots.
 

alamatnitotoy

Honorable
Sep 2, 2012
7
0
10,510
thanks for the reply.., actually I have already tried removing all of the components leaving only the cpu, 8 pin and 24 pin. still same issue. done this while mobo is outside the board