Fried CPU or Mobo : PLEASE HELP!

By Mandor ยท 7 replies
Feb 12, 2006
  1. Hi all,

    We recently had some electrical problems at my place (breakers shutting off for no reason) and i decided to use an extension (plugged in a safe outlet) to power my powerbar, in which my computer is plugged in.

    Now here's what happened : The power bar was switched OFF, monitor, speakers and computer plugged in with all their switches set to 'I'. I plug the power bar in the extension, and I hear a crackling noise followed by a faint burnt stuff scent. I'm like ... ok, the power bar isn't even switched on, so i switch it on. Monitor and speakers power up correctly, so i press the panel power button on my comp to start it.

    Fans start to spin, red HDD LED stays lit, but not the blue power LED, and computer self shuts-down after 1-2 minutes. NO beeping sign. NO signal on the screen.

    I'm like .. ok, I fried the PSU, so i take the PSU off from my other PC and plug it in. Same symptoms : HDD let stays lit, fans spins, no signal, no beeps, and it shuts down after 1-2 mins.

    So i take my investigation further ... I unplug everything except the 24-pin ATX and the 4-pin CPU power plug. Same thing .. no beep, red HDD led lit up (less intensity, but still lights up) and comp shuts down after 1-2 minutes of nothingness.

    SO i kind of narrowed it down to Mobo/CPU .... but which one is it? I dont have extra hardware to test and i dont have any money to buy some just to test.

    Any guesses?
  2. SOcRatEs

    SOcRatEs TechSpot Paladin Posts: 966

    Hello! Welcome to TechSpot!

    Well, it could be the psu or the MoBo. Most likely the MoBo.
    If you have another system that you pulled the second psu
    out of, is this a working system? If so you'll need to check
    everything from the fried system on the working machine.
    I'm pretty sure the cpu is ok.
    Pull the ram and check it on the working system.
    Then the cpu, then video card, hdd's, cdrom's and so on, till your down to
    the MoBo and psu in the fried system.
    Next I would pull the suspect psu and try the known psu on the fried system,
    with the original MoBo still in place, cpu, one stick of ram and video card.
    You can try this in any order just be sure your checking each item.

    It seems odd to me if the power strip was off, how it could spike your system.
    I would not trust this power strip at all.

  3. Mandor

    Mandor TS Rookie Topic Starter


    Thank you very much for the fast reply Socrates.

    The system i pulled off the second PSU is currently working (im typing stuff on it right now!) so I assume the PSU is not the problem since the system still would not work with this *working* PSU.

    Now as for the parts testing, I am pretty limited since this system (that i'm using) is my father's Intel system. So I obviously can't put my S939 opteton in it.

    So if i'm sure it's not the PSU, its either the MoBo or the CPU.

    Would a fried CPU give me the same symptoms or is it definitely the MoBo. If it is, i'm off to buy a new MoBo tomorrow.

  4. SOcRatEs

    SOcRatEs TechSpot Paladin Posts: 966

    Unless the AMD cpu melted into the socket, I'm betting it's the mobo.
    If not the MoBo make sure you can return it before you buy.
  5. Mandor

    Mandor TS Rookie Topic Starter

    Will do. Thanx M8!
  6. Mandor

    Mandor TS Rookie Topic Starter


    I had the chance to test the board tested and its dead.
    thanx for the heads up !
  7. TheKolkster

    TheKolkster TS Rookie

    Could this have caused a power spike?

    Were you able to test your CPU also? Cause the no video tells me it either shorted out your BIOS (which would just need a reset) or a fried CPU. And what confuses is me is you said you were able to turn your computer on. If the motherboard was fried, wouldnt it not turn on?
  8. DragonMaster

    DragonMaster TS Rookie Posts: 327

    OK, here's what happened : When the power bar is off, current can't get to the computer, but the capacitors in the PSU are still charged and when you plug the power bar, the charge from these capacitors probably got out. You might say yay, current got out of them, but how could it have damaged the rest? The spark is the problem. It created interference and probably sent unwanted things to the rest of the computer. I suppose it's that because I scrapped a TV like this.

    Also, if the polarity of the power socket is reversed, current goes to the components even if the power bar switch is off(But the current can't return-- except with the ground pin)

    Don't use cheapo powerbars is possible too. I think that even APC surge protectors are a bit bad. I know one that stays on on both off and on position...
Topic Status:
Not open for further replies.

Similar Topics

Add your comment to this article

You need to be a member to leave a comment. Join thousands of tech enthusiasts and participate.
TechSpot Account You may also...