Computer does not boot after power down, PS problem?

Hi All,

I am experiencing a very strange hardware problem. My system is an Athlon64 3000+ with an Asus A8V motherboard, 1024MB of RAM, ATI 9600PRO AGP and various harddrives and dvd drives. It is relatively new, running since December 2005. The power supply is an Enermax, 330W. I run both Gentoo Linux and Windows XP. Gentoo runs fine, but the Windows side is a bit buggy, mainly focused around video card errors (i.e. lockups/restarts during games), but nothing too terrible. The motherboard beep codes at startup are a bit wacky, though, sometimes just the single beep, but more often two beeps (the first normal one, and the second either higher or lower in pitch). A few times I get a longer beep followed by two shorter ones, which I believe is supposed to indicate a video card error, but the machine continues to boot and run as usual. I can't find an explanation for the other beep codes.

My first idea was that I had some bad RAM, causing some of this weird behaviour. But, I ran Memtest86+ for about 5 hours with no errors on a couple of different occassions. The memory is pretty decent (OCZ). So, I figure maybe some bad video drivers in Windows (I tried a bunch of different driver versions, but no real change), but in general it all runs fine so I can live with it.

But, here is the very strange problem. Over the last few days, once I power down the machine I can't turn it back on. Pressing the power switch does nothing - no fans, no drives, nothing. Occassionaly, it will very briefly appear to be starting (i.e. lights, fans, but for less than a second), but then go dark. The green LED on the motherboard is on, but that is it. I thought at first that maybe there was a short somewhere (I built the machine myself), so I took everything apart, cleaned it up and re-positioned a post that looked a bit off. I thought I had it, as it ran great for a day (turned on and off fine), but it has since returned to its previous strange behaviour. The only way for me to get the machine back on is to completely unplug it and let it sit for a while, then plug it back in. So, it seems maybe the power supply is wonky, but, once the machine starts it runs fine and the voltages and temps seem to be fine. Just to be sure, I took the power supply out and tried it in an other computer - worked fine, no problems. I also thought it was maybe a switch problem, and tried to directly short the power switch pins, but that didn't work either. The last thing to do, I suppose, is find another power supply and see if the problem continues. However, all my other computers are a bit older and don't have the proper 4-pin 12volt connector neccessary for the A8V, so I would have to go out and purchase a new one (which I would rather avoid doing if it is unneccessary).

So, my question is: has anyone ever experienced this sort of behaviour? Is this a power supply problem, or the motherboard? I've examined the board and don't see any funny capacitors or other signs of distress. I'm pretty confident in my computer skills (both hardware and software), but this one has me stumped. Could anyone possibly lend a hand with some advice?

Thanks very much,
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  1. man i think the 9600 cards are buggy or somtihn, i had one similar to that and what happened sometimes was the card would overheat i guess and turn off my entire computer, it wouldnt turn on for about 20 min after that, finally it just burnt out and died. id suggest looking at a better video card. but things to check are temperatures and making sure everything is seated properly. 330 watt psu is plenty for what u have, unless theres like 5 harddrives in there. i didnt read the entire post because it was kinda long and im lazy so this might not help... but i pray it does
  2. as you said, there are 2 options: motherboard or PSU. I think it's the PSU, but you can't know well 'till you try with another PSU. Btw, did you reset the BIOS?
    Also, try to power your system with minimal hardware configuration, without the video card. Good luck !
  3. Thanks for the replies!

    I went with a new power supply, and that seems to have been the problem. Everything is booting up properly (or at least, has been for the last 12 hours or so). But, the video card still seems wonky. It's only a year and half old, but I guess it may be time to get a new one.

    Thanks again,
  4. Quote:
    9600 cards are buggy or somtihn

    yah thye are, my bro's room mates PCcrashes often while hes playing.
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