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Possible CMOS batery failure?

By CarpeMofo
Dec 1, 2011
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  1. I've already ordered a new CMOS battery, but I'm anxious to know if this will actually fix my problem, so I was hoping maybe someone could offer insight.

    Alright, so I tried to start my computer one day and and got the post beep that says everything is a-ok. My monitor powered on, but I got nothing but a black screen. I pulled the video card, reseated it. Same thing, so following the tried and true methods of troubleshooting, I removed everything that didn't have to be in my machine, trying all four sticks of my ram one at a time. Still, bios beep, monitor power, not post message. So I bought a new video card popped it in, exact same problem. Returned the video card and decided to RMA my motherboard. (Gotta love Asus with there 5 year warranties)

    Took apart the whole machine, cleaned the mobo which included popping out the CMOS battery to get some dust that was around the edge, and put the mobo in a metalized bag. Tried to call Asus on a Monday to learn they were still on vacation for Thanksgiving so I figured why not and decided to put the whole computer back together to do some more testing. And it booted right up, ran an update, restarted, same problem, so on a hunch I removed the CMOS battery for all of thirty seconds, popped it back in and sure enough my computer started right up. Since then I've restarted it about half a dozen times, each time the only thingt that fixes it is removing the CMOS battery for a short period of time and putting it back in. I did try to replace the battery with one from another computer and it didn't work, but that computer hadn't been started in over three years... So do any of you think that the replacement with a new battery will fix the issue? Or do you think there is something actually wrong with the mobo itself? Like the actual CMOS chip?

    Sorry that this is so long, but I like to be comprehensive when posting to a support forum!
     
  2. lipe123

    lipe123 TS Evangelist Posts: 658   +174

    Power supply?

    Each time your turn it off for long enough to remove the battery its also enough time to give the supply a good rest.
    Even with no battery in the system it will boot up every time and as long as you don't unplug the power or switch off the PSU the settings will be saved just fine.

    The only reason the battery is there is when the computer has no power at all.

    Also try just updating the bios or reflash if with the same version if its already on the latest just in case the bios itself somehow got corrupted.
     
  3. CarpeMofo

    CarpeMofo TS Rookie Topic Starter

    Nothing to do with powering it off.

    I can unplug the power supply for hours and the computer won't boot, not until I remove the CMOS battery. Of course I have to reset the BIOS every time I do, but just unplugging the PSU won't allow it to boot.
     

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