PC starts, but doesn't beep, the screen says No Signal ... and more...

Hello, lately I've been experiencing issues with my PC booting, it's not new or anything.

CPU: AMD Phenom X2 3.1ghz - bought in 2010
MB: ASROCK 790gx pro - bought in 2010
RAM: 4GB DDR3
HDD: 500GB - bought in november 2013
GPU: Gigabyte GT630 2GB DDR3 - bought summer 2014
PSU: - they installed me a new one with the GPU, so its from summer 2014 as well


in around September/October I've been experiencing the PC waking up on its own while sleeping, which at first I was OK with
in the end of October, when it got cold outside, one morning I attempt to start my computer (clean boot, no waking up) and I hear the fans starting and at the time it's supposed to release a beeping sound, it shuts down, I remove the power cable, plug it back in, the PC starts on its own, without me even pressing the power button, it still reaches the same point - before the beep and shuts down again

at that point I figured that the hardware might be too cold to start (it was cold in my room then) so I go get the hair dryier, unplug the PC power cable and blow some heat trough the opening on the left panel, after about 10 seconds, I plug back the power cable and the PC starts running as it should, until the next day, then the same thing happens again

I've put up up with this for about half a month and yesterday I got really annoyed, after the hair dryer procedure, I went to the BIOS settings and looked for something unusual, then set them to default and saved, then the PC suddenly turns off and the next time I try to boot it, it just starts the fans and keeps running without the beeping sound and the screen doesnt start, when I manually start it, it says "NO SIGNAL"

so i open the PC, check all the PSU cables, check the RAM, i tried everything on the checklist, my CPU has thermal paste and everything, I still can't get it to start

at this point I'm willing to do anything to fix it and get rid of it and buy a new one, I'm asking you guys to help me find out if the PSU or the Motherboard is at fault, because I can't think of anything else, but eventually I will get a new PC or laptop


thank you!
3 answers Last reply
More about starts beep screen signal
  1. I suspect it's the PSU there but there is really no way of eliminating a PSU fault without a 'known good' PSU; all the readings can be fine on a multimeter but the PSU can still be faulty.

    In your case, I would breadboard just your Motherboard, with CPU, RAM and video card to eliminate a short circuit, check the CPU pins closely (very closely, as in go over each pin with a torch and look at the pins from every angle). Also see if you get an error tone when you try to boot without the video card and then without any RAM installed.
  2. anti-duck said:
    I suspect it's the PSU there but there is really no way of eliminating a PSU fault without a 'known good' PSU; all the readings can be fine on a multimeter but the PSU can still be faulty.

    In your case, I would breadboard just your Motherboard, with CPU, RAM and video card to eliminate a short circuit, check the CPU pins closely (very closely, as in go over each pin with a torch and look at the pins from every angle). Also see if you get an error tone when you try to boot without the video card and then without any RAM installed.


    Yesterday I tried without the RAM - no error sound
  3. OK, sorry for reviving this thread again.

    I've managed to get the PC to work again. When I tried to remove the CPU heat sink, it didn't work, when I pulled harder, the whole CPU got pulled with the heat sink. Apparently it was stuck to the thermal paste, so I removed it from the heat sink, all the pins seemed intact, so I plugged it back in, now my PC starts again.

    But the problem with using a hair dryer to get it to start every morning still persists. I've also noticed that the first time trough the day if I try to start it without the hair dryer it doesn't reach the bios beep and turns itself off again. If I unplug the power and turn the switch from 0 to 1 again, it boots up own its own, without me having to press the power button, I can reproduce it every time, until I use the hair dryer to warm it up enough to boot properly.

    I'm starting to feel that the problem lies within my PSU, which was replaced when I bought that graphics card, but I'm taking it to a service store nevertheless.

    I would like to hear your thoughts on this outcome, please... and have a great day!
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