Bios resets if unplugged, but not if only switch off? Always keeps time; + new CMOS battery

[Goldenvoice]

EVGA 131-GT-E767 I'm experiencing some strange BIOS behavior. If I unplug her for a while, the BIOS will reset the sleep mode from S3 back to S1, and my custom fan settings will be lost.

First step was to change the CMOS battery, even though it always seemed to remember the date and time; that didn't change anything (except I then had to reset the date and time, of course)

So this evening, I decided to shut 'er down, then turn off the switch on the back of the PS (XFX Black Edition P1-750-CAG9), but leave her plugged in... waited 30-40 minutes, flipped the switch back on, and started her up...

Sleep mode is fine, and the fans retained their custom settings. Any idea what I may be dealing with here? We loose electricity maybe once a year, so not a big deal to reset those 2 BIOS settings, but it would be nice to know it's not indicative of deeper issues - It simply has me stumped.

Thoughts?

 

[GhislainG]

If you changed the CMOS battery, then it can keep the settings even when the PSU is powered off; that's the purpose of the battery. Did I misunderstand what you wrote?

 

[Goldenvoice]

I did replace the battery - a couple days ago - it didn't make any difference. The time/date stays correct regardless: old battery & new battery.

IF I unplug the computer from the wall to, say, dust it out, or whatever, when I plug it back in, and start it up, the BIOS has lost my sleep setting (S3), "wake up from USB", and my "Smartfan" settings. It reverts to the default settings, just as if I pushed the "clear CMOS" button...

I thought about it today, and realized perhaps the reset button on the back panel was held down (not lined up with it's access hole) or something, but that doesn't seem to be the case. I tried manually resetting with the button, and that, too, reset the CMOS / BIOS to default... but didn't loose the time...

So BIOS custom settings revert to default when unit unplugged, but the time/date is just fine...

 

[Goldenvoice]

OK, gathering more details.

I just shut her down, and unplugged her fo 5 minutes; plugged back in, and started.

POST does an odd double-start thing. It starts the moment I push the button, and almost immediately stops, then starts back up again. This it does not do if I leave it plugged in.

On this 5 minutes unplugged test, the BIOS settings did NOT reset...

I'll have to try a longer unplugged version to see what happens. I suppose there's some odd chance each time I've been in the case, I've inadvertantly pushed the onboard "Clear CMOS" button - that would be strange, but brainstorming says anything is possible.

 

[GhislainG]

If replacing the CMOS battery doesn't help, then you'll have to swap the motherboard.

 

[murraymuzz]

I just had a similar problem and it was because my cmos jumper wasn't in the normal position maybe check that.

 

[Goldenvoice]

Well, I guess I get some kind of award for being clueless. Left it unplugged all night, plugged it in and fired it up this morning, and all is well...

I must have inadvertently touched the BIOS reset button each of the last couple times I've been in the case lately; once was a full R&R to make extensive case mods, the next to pull the PS down to service the PS fan... (which did require removing the audio card - which requires removing several leads from the MB first - which snuggle up close to the reset button. I now see the value in having a jumper over a button)

This is so like me to over analyze problems that don't really even exist.
So it looks like at this point, I'll call it healthy, and me crazy 😉

***OT: how come on this post I have to sign in to see any replies - but not on other threads in the forum?

 

[GhislainG]

You have to logon because you own this thread and you can modify your own posts.

 

[Dark Lord of Tech]

This happened to an Asrock board I had , sent it back and with the new board no issues.

Get a new board.

 

[GhislainG]

Good advice if it still is under the 2 years warranty.

 

[Goldenvoice]

No, it's no longer under warranty. I do think I may have been responible for the resetting. I'll unplug it again tonight, but I do believe I'm in the clear