dead mobo or PSU?

By greeny12m
Sep 14, 2007
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  1. hey guys.
    i recently instaled Vista on my PC and turned it on the other day, the fans spin and hard drives spin up. but nothing else, no post, it wont even turn off when i hold the power button or beep at me if there is no RAM plugged in. its an ASUS P4S800 mobo. i have taken out the battery to try and clear the cmos but still nothing.
    im thinking it is a fried mobo, but could it be the PSU? if it is the PSU any ideas on replacements?
  2. raybay

    raybay TechSpot Evangelist Posts: 10,716   +6

    Have you tried to startup the computer using SAFE MODE where you press the F8 key about once per second. If you get something on the screen then, you know the problem is in VISTA
    Doesn't appear to me you have a bad psu with what you describe.
    You can buy a power supply tester for about $10 at CompUSA, Frys, and other computer service stores, or online atg www.cyberguys.com.
    A simple test is to watch the power supply fan blades from the back. Then as you turn on the power switch, watch to see if the fan blades in the power supply turn one quarter to 2 3/4 turns then stop.
    There are a bunch of simple tests for that motherboard online at the ASUS site.
    However, the likely problem ties back to the VISTA install. Reformat the hard drive and reinstall VISTA, after you have all the drivers downloaded for that motherboard... and for the video card... for VISTA... You are likely missing something so obvious you overlooked it, as most of us do.
    Also, memory is a common cause on an ASUS board... as is the video graphics card.
    Still, I feel it all goes back to the VISTa install, and the follow up drivers.
  3. system7

    system7 Newcomer, in training Posts: 16

    greeny, this is going to take a few posts to track down.

    It looks like a hardware failure to me. Unplug your machine before doing stuff, and touch the case before components to avoid static problems.

    Disconnect the hard drive to take Vista out of the equation, any peripherals, and clear the CMOS with the power unplugged by taking out the CMOS battery. I wouldn't be sure you even have a motherboard loudspeaker here, looking at the ASUS P4S800 page.
    http://www.asus.com/products4.aspx?l1=3&l2=12&l3=42&model=199&modelmenu=1

    With just a keyboard and onboard graphics display, try swapping around a single stick of RAM, because RAM can fail unpredictably, and prevent a boot.

    If you still can't get signs of life, it's unlikely the processor has failed. So you are left with motherboard and PSU as the culprits. Assuming the 20 pin power supply is decent, with overvoltage protection, you are free to test either with known good components. So you can try the PSU in another machine, or borrow another supply for your motherboard. 300W PSU will do nicely with your spec.

    Tedious, isn't it?:)
  4. greeny12m

    greeny12m Newcomer, in training Topic Starter Posts: 34

    thanks guys, i have worked out that it was a fried motherboard, it used to beep on power up, and it would continuously beep if no ram was plugged in, and now it does neither, although not sure how it happened. one day it worked the next it didnt.
    Any suggestions for a replacement? it needs intel skt 478. Pc3200 RAM and AGP8x preferably with SATA connectors but this is not necessary
  5. raybay

    raybay TechSpot Evangelist Posts: 10,716   +6

    If you want to sell the old one, name your price.

    On whatever new one you select, take great care in reconfiguring the board. Oftentimes, the failure is not caused by something about the motherboard. Any electrical failure in the power supply, cpu, cpu fan, video graphics card, power switch, modem, ethernet card, sound card, or memory can cause the motherboad to go... and may cause the new board to fail in a similar way.
  6. system7

    system7 Newcomer, in training Posts: 16

    There's not many around...

    Best AGP socket 478, DDR and IDE/SATA compatible type I know is this Asrock P4i65G one:
    http://www.novatech.co.uk/novatech/specpage.html?ASR-P4I65G

    Explain to Microsoft that your board blew up, and they will reactivate your old Windows for you. You may have to be insistent on this, depending who you talk to, but Microsoft are good people at heart...:cool:
  7. raybay

    raybay TechSpot Evangelist Posts: 10,716   +6

    Well, sometimes.
    The Microsoft official position is that the Windows install dies with the motherboard, if you are using a recovery disc set.
    Do not talk to the automated system. Request to speak to a live person. Most of these people are in Canada, and are very nice about helping you.
    Once you have a live person, they will ask you if your Windows is installed on more than one computer. You will need the code you get on your screen.
    It is not fast, but is relatively simple.
    If your Windows is installed on a number of other machines, or if your version has been installed on a number of machines recently, or more than three machines since the release, they will ask you a lot more questions.
    If what you tell them is later determined not to be true, you will occasionally get a box on your screen saying the windows install is unauthorized.
  8. greeny12m

    greeny12m Newcomer, in training Topic Starter Posts: 34

    thanks guys i wont have any problems with the windows, its just the motherboard. is there any chance of fitting a Micro ATX from factor in my ATX case, i know theyre different sizes but thought maybe the screw holes might line up??? i thought it would be cheaper than my old board to get a new one, but it looks like it might be more expensive, 3 years on!!!
  9. system7

    system7 Newcomer, in training Posts: 16

    Asrock boards are at the small end of mATX size at 9.6"x8.2". Probably only needs 6 standoffs. Asus mATX is usually the full 9.6"x9.6" and need 8 standoffs. I'd be amazed if it doesn't fit in an ATX size case. These things are downward compatible.

    It is fitting a bigger ATX type in a mATX case that needs a bit more effort:
    [​IMG]
    HEHE ;)
  10. greeny12m

    greeny12m Newcomer, in training Topic Starter Posts: 34

    ray bay you sure you want a burnt out old motherboard? its yours for $15. unfortunately postage from the UK will be quite a bit i fear.
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