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Interesting problem I've got going on - I have a Biostar TZ77B motherboard. This morning I awoke to a computer that POSTed successfully but wouldn't display anything on screen. I finally removed my EVGA GeForce 8800 GTS card and the display output shifted to the on board video. Once there, I could see a "CMOS Failure" message. Changing a BIOS setting cleared the message (basically just 'save and restart').

I figured my GFX card had died so I'd live with on board video for a few days. However, now running on on-board video - when Windows puts the monitor to sleep (power saving), the monitor won't wake up. After a hard reboot I get the CMOS failure message again!

I don't get the CMOS failure message after every reboot or after leaving the system off - there seems to be some mysterious correlation between display and CMOS failure. I'm not even certain at this point if my GFX card has truly failed or not - windows can recognize it just fine (when I'm leveraging the on board video to actually see an output:) but nothing comes to the monitor when I display it as primary.

Pretty odd - any ideas? I'm going to swap the CMOS battery now out of curiosity.

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Not sure what you're asking. You have a reported CMOS failure - replace the CMOS the battery, if that doesn't help then you need to replace the motherboard (since that's where your CMOS lives). – Ƭᴇcʜιᴇ007 Jul 7 '13 at 16:25
CMOS battery swap did not resolve. What I'm trying to get at is that the "CMOS Fail" message doesn't stop the computer from booting (not directly at any rate - it loses my AHCI setting when I get this message so windows won't boot, but I can fix that in the BIOS and I'm good to go again). I'm trying to get to the bottom of what on earth power saving on a monitor may have to do with loosing BIOS settings and this "CMOS Fail" message. I reckon I'll try a BIOS update next. – Jason Seemann Jul 7 '13 at 16:43
Also - I have tried the "CLEAR CMOS" jumper as well, no effect. I've also restored BIOS settings to Optimized Default, no effect. – Jason Seemann Jul 7 '13 at 16:45
up vote 0 down vote accepted

For the record - it seems that a combination of replacing the battery, clearing the CMOS, and updating the firmware (respectively) has resolved this issue.

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