Biostar TA790GXBE board has stopped powering up

Discussion in 'PC Hardware' started by doveman, Aug 4, 2012.

  1. doveman

    doveman MDL Member

    Apr 22, 2010
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    #1 doveman, Aug 4, 2012
    Last edited: Aug 4, 2012
    I've had my Biostar TA790GXBE on the bench for a while but got round to ziptie-ing the fan to it yesterday and put it in the case but now it doesn't power up. When I switch the PSU on I see the board LEDs flicker on briefly, which is what they've always done so obviously power is getting to the board, in part at least. I've taken it back out the case and it still won't power on.

    The thing is, the board has power/reset buttons built onto it and the power one stopped working some time ago but as I could still power it with the switch attached to the front panel header block I wasn't too bothered. So perhaps there's a problem in that area that's spread to the header block as well now? Could it be a dry joint? I guess I could try and fix it myself if so, but if I'm lilkely to send it back for repair I can't mess with it at all. I bought it on 3 June 2010 though so I doubt it's still in warranty.

    It's a real pain because I was planning to send this PC to my brother for his birthday in 3-4 weeks. He's got the box for the motherboard, so if I have to send it for repair I'll have to get him to post that to me before I can send it off and then who knows how long it will be before I get it back. I thought I could buy another motherboard if it's possible to get one that's more or less the same (i.e. 790GX chipset) so that I won't have to reinstall Windows 7 x86 from scratch and then sell the repaired Biostar board when I get it back. If I'm going to do that I need to make sure there's a SLIC BIOS mod for whichever replacement board I get though and that it has much the same features/connectors, etc although I guess I could switch to a DDR3 board and sell the DDR2 RAM.
     
  2. LatinMcG

    LatinMcG Bios Borker

    Feb 27, 2011
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    similar board/ issue.. was power supply.
     
  3. doveman

    doveman MDL Member

    Apr 22, 2010
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    I just tested the PSU by shorting ATX PS_ON to ground and it powers on like that.
     
  4. wintron

    wintron MDL Member

    Dec 4, 2009
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    if the board is out of its case you could also short the two pins on board which are the ones to power on . power switch

    then it could be the power switch
     
  5. doveman

    doveman MDL Member

    Apr 22, 2010
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    Yeah I thought of that but I don't really need to as I've tested with the case switch and a spare loose one which I was using when the board was on the bench and I doubt both switches are faulty.

    I Should mention that I did try powering it up by WOL yesterday (which I confirmed was working from standby a week or two ago but haven't tested from off before) and that didn't work either, so it might not just be the on-board power button and header that's faulty. That just seems like the obvious candidate area considering that the button stopped working a while ago.
     
  6. wintron

    wintron MDL Member

    Dec 4, 2009
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    with a small screwdriver shorten the two pins on the board where the power switch connects that will eliminate the actual power switch/es
     
  7. doveman

    doveman MDL Member

    Apr 22, 2010
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    Yeah, I know what you're suggesting I just don't believe that two working switches have suddenly died on the same day.
     
  8. LatinMcG

    LatinMcG Bios Borker

    Feb 27, 2011
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    mine did too.. but was weak or something.
     
  9. doveman

    doveman MDL Member

    Apr 22, 2010
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    I just don't think it's likely to be the PSU as it's fairly new and was working fine when I had the motherboard on the bench the other day. I'll have to buzz out the button and header on the motherboard and then test the components on another board I guess. :rolleyes:
     
  10. LatinMcG

    LatinMcG Bios Borker

    Feb 27, 2011
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    make sure u didnt forget the black n yellow power plug
     
  11. doveman

    doveman MDL Member

    Apr 22, 2010
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    No, I didn't.
     
  12. doveman

    doveman MDL Member

    Apr 22, 2010
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    OK, I've tested the PSU on my MSI board and that works fine. I've also tested with another power switch on the motherboard, which I buzzed out to confirm it's joining the two points on the back of the board, so the problem's obviously upstream from that. The onboard buttons don't seem to be connecting their two points, so either both buttons are faulty or there's a fault in that area of the board.

    Not looking forward to the next step, which is to strip my Gigabyte board out the case, remove the CPU heatsink and CPU and test this CPU and RAM to be sure it's the board that's faulty.
     
  13. QuantumBug

    QuantumBug MDL Developer

    Mar 7, 2012
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    How old is the board? May be bad capacitors.

    You'd need to test each cap with a multimeter. I usually remove each one and test accordingly.
     
  14. doveman

    doveman MDL Member

    Apr 22, 2010
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    I bought it in June 2010.
     
  15. QuantumBug

    QuantumBug MDL Developer

    Mar 7, 2012
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    Great, update me on how it goes. I know some awesome tutorial videos in case you need to replace them :)
     
  16. doveman

    doveman MDL Member

    Apr 22, 2010
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  17. doveman

    doveman MDL Member

    Apr 22, 2010
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    Well I got the replacement TA790GX A3+ board today and fitted the CPU and 4GB DDR3 my Dad had spare after I upgraded him for his birthday. Still doesn't work!

    Seeing as I've tested all the other components, either the CPU's dead or I've been sold a faulty motherboard but I don't think the latter's likely as the seller has 100% feedback.

    So I'll just have to strip my Gigabyte system (the worst part is taking the Thermalright SI-128 SE CPU heatsink off) and test the Phenom II X3 720 from that on this new board (and the old one for that matter). At least if the CPU is faulty it's got a lifetime warranty, so I'll just give my brother the Phenom II X3 720 and put the replacement Athlon II X4 640 in my Gigabyte system when I get it back.
     
  18. doveman

    doveman MDL Member

    Apr 22, 2010
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    #20 doveman, Aug 21, 2012
    Last edited: Aug 21, 2012
    (OP)
    Man this is doing my head in now. I've put my Phenom II X3 720 in the TA790GX A3+ board I bought and it still doesn't work. Does much the same as the TA790GXBE board did, the leds briefly flicker on when I first try to power it up with the onboard button or the case button (not on subsequent attempts until I power-cycle the PSU) and that's it. I've put the Athlon II X4 640 in the Gigabyte board and that works fine, so I don't know what's going on unless the TA790GXBE board died and the TA790GX A3+ board I bought is also faulty.

    EDIT: Although I'd already tested the PSU on my Gigabyte system with the PSU out of the case, I just tested again (with the X4 640 in the Gigabyte board) with it in the case, just on the off-chance that there was some weird problem making it not work properly when screwed into the case but it worked fine, so it's definitely not that.