Something in my system is blowing mobos

By ajrDeveloper
Sep 10, 2009
  1. Hi I run a small company, I bought 3 identical PCs from the internet, all in bits and assembled them myself. I have been assembling PCs myself for about 7 years so I would like to think I knew what I was doing.

    Intel Core2 Quad 2.66
    Corsair 2048MB 1600Mhz RAM (x2)
    XFX nVidia 790i Ultra mobo
    XFX GeForce 9800 GTX+ g-card (x2 SLI)
    CoolerMaster 1000w SLI PSU
    CoolerMaster Chassis
    LG BlueRay, HDDVD, DVD, CD, lightscribe Optical drive (don't buy them they're crap!)
    WesterDigital 500G sata2 HardDrive (can't remember the spindal speed, doesn't really matter)

    One day one of them froze up while scanning something in, they don't really crash and certainly have never locked up like this one did. I thought nothing of it and rebooted the system. The mobo wouldn't post, stuck on FF. Read a few forums on these mobos doing it, can be faulty ram, fried CPU, short on the board or PSU fault. Easy problem to diagnose, stuck the Ram and CPU in another one, booted fine so I put them back. I ripped the g-cards out the faulty machine and powered it with another known working PSU (these mobos will still post with no g-card, I tried it on mine) still wouldn't post. I pulled the mobo out and stuck it on an antistatic bag in case the chassis was shorting it although nothing was protruding and all the stand-offs were in tact and in the right place, still not posting. Got to be the mobo right? WRONG!

    I RMAed the XFX mobo, they are now discontinued so I got an ASUS with the same chipset, a striker II its called. Stuck all the bits in the chassis, tried it lying on its back, turned on and posted fine, I couldn't get it to go into the bios setup which was a bit odd and I had to manually restart but it booted into windows, a few errors which looked like some driver conflicts nothing that concerned me. So switched it off, stuck the cover back on and stood it up, plugged everything in (mouse, network, monitor, usb devices etc..) ...and... it wouldn't post! GREAT!

    I ripped EVERYTHING out of mine, replaced my motherboard with the new one and put EVERYTHING from mine onto the new mobo, inc chassis, screws, CPU, heatsink even the power lead. Still wouldn't post, it gets stuck on CPU INIT and from what I can gather on other forums its the same as FF and the same diagnostics ie, PSU, CPU, Ram all of which I know work because they came from the computer I am talking to you now on!

    So what is clear is that the mobo's gone and I think its safe to assume that something else in the computer is blowing them up! The only things I didn't try is the PSU in my computer, the installation of windows in my computer, the g-cards in my computer, and my computer in the chassis all of which I feel could potential blow my mobo so I'm not going to try!!!

    I am wondering if this story is familiar to anyone and if anyone has any suggestions. I may of been putting computers together for 7 years but this has never happened and lets be honest its not hard! I probably need a REAL specialist to look at it but the problem is most "PC Specialist" only know what I do, if that!

    I hope someone can help and thank you for reading this far!
  2. Kcircyrd

    Kcircyrd TS Rookie Posts: 216

    What can do it? Power supply. Improperly grounded board. Defective hard drive or other drive. Defective jack...
  3. ajrDeveloper

    ajrDeveloper TS Rookie Topic Starter

    Just had the power supply tested, its fine! The entire chassis is a metal conductor, strapped to a £150 top spec tested PSU and two mobos unable to ground themselves?

    Defective hard drive, can a hard drive kill a mobo? (I don't know)

    Which jack and again, killing one of the best mobos on the market?

    It just doesn't make any sense, I'm wondering if its pure coincidence that two mobos just happened to do a similar thing before dying but it just sounds too coincidental.

    I think I'm going to send them back to the net company and get them to find it else its going to be an expensive diagnostic for me.
  4. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,233   +234

    It has to be something with the case/power supply... I had a similar problem with a computer, where the power supply had 100 volts on the outside of its metal case. Testing it outside the case, every voltage was fine. When it was installed the 100 volts was present again. I got shocked, that's how I found the problem
  5. Kcircyrd

    Kcircyrd TS Rookie Posts: 216

    Yes, a hard drive can damage an entire system. We have seen defective drives short out boards, but we assume they were damaged in shipment.
    We have also seen defective motherboards (Asus boards (no less - and from NewEgg - go figger) from a bad production run with defective component that caused them all to fail, but that was three years ago.
    Please keep us informed if you discover the cause. Interesting to us. Agony to you.
  6. ajrDeveloper

    ajrDeveloper TS Rookie Topic Starter

    Well we needed some work off the hard drive so I plugged it into an old system that didn't matter if it went pop. I managed to grab the data without any problem, I don't know if it would make a difference with it not being the boot drive but it didn't cause me any problems.

    The net company who I bought it all off have been pretty good. They are happy for me to RMA everything so they will test the lot and send back whats okay and fix what isn't.

    What I'm worried about is that it's all going to be tested and come back okay!
  7. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,233   +234

    "Yes, a hard drive can damage an entire system"...

    In all my experience, a hard drive can make a computer lock up or not post at all, but damage an entire system... I say no way!
  8. ajrDeveloper

    ajrDeveloper TS Rookie Topic Starter

    When you say not post at all, do you mean while the hard drive is plugged in, or the hard drive stopped the mother board from posting full stop?
  9. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,233   +234

    It is very rare for a bad hard drive to keep a computer from POSTing. If the hard drive is not detected by the bios, the POST could be delayed. From not booting is another story
  10. ajrDeveloper

    ajrDeveloper TS Rookie Topic Starter

    Well that's what I thought, even the guys that came in looked at all the hardware all said, "This shouldn't be happening, you've bought the best so everything should be protected."
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