CMOS problem
 

I recently got a motherboard/chip from a friend, and I installed it in my box with my old harddrives and RAM. I turned the machine on, and everything was working fine. Everything worked for a few weeks, but then the machine needed to be rebooted, and it wouldn't reboot.

I reboot the machine, and it constantly beeps from the internal speaker, three beeps at a time. If I turn the machine off, open the case, and put the jumper to reset the CMOS, then put the jumper back, I can get the machine to turn back on, once. If it needs to reboot, it fails turning on again, continually beeping.

When I reset the CMOS, and reboot the machine, I note on the screen "CMOS Checksum error - Using Defaults" or something along those lines. The clock is always set at Jan 1, 2001. I've switched out the battery with one I know is functional, I can't think of anything else that would be causing this. Any suggestions?

Resetting the CMOS causes the error you mentioned.
Also resetting may/will cause the clock to reset, so these things do not point to an error.

What kind of motherboard and proc do you use?

Does turning the system off for a few hours and then booting work?

Have you tried disabling the "Quick Memory Check on bootup" (or something like that) in your BIOS?
(i had a similar problem that was solved this way)

Please give us more details.

Silvy

I don't think the reseting the CMOS is causing the problem. If I reset the CMOS, the machine reboots and gives me that error. I can choose F1 to continue, or DEL to enter setup. If I enter the setup, and set some settings, and save the CMOS and exit, I get that beeping error again.

I will try looking for that quick memory check thing.

I'm not sure of the motherboard type, I think the chip is a Duron 600.

I couldn't find an option for any memory options.

On boot, the screen says:
Award Modular BIOS v6.00PG
Copyright 1984-2001
MK33 R1.14 Jun.07.2001

Still can't find anything about what the version of the mobo is.

Ok, AMD chips are known to have power issues (is they require a lot of it)
Older power supplies can have problems dealing with the sudden jolt of booting the processor AND running through the memory like crazy.

I think this explanation sounds a little bogus, but it was given to me together with the 'quick memory' solution. And it completely solved my AMD K6-450 problems which sound a lot like yours.

Good luck!

Sounds like something may be touching the CMOS clear pins or one of the traces leading to it, maybe shorting it...

Perhaps the motherboard's battery is dead?

happened to my brand new p4p800 mainboard: the clock wouldn't run properly. After replacing the battery, it's working fine.

No, I've switched the battery out to one from another board that I know still has juice, no luck.

When you reset the CMOS, it drops it back to factory defaults, including the date.

This is likely not a CMOS issue, rather a hardware issue elsewhere. Drop a new PSU in there as well, if the current one is more than 2 years old and / or less than 350 watts (350 is min, unless you don't have a power hungry vid card.)

I'm starting to think now it's a memory incompatibilty issue, though there wasn't a problem with these DIMMs on my previous board. I'm going to try multiple combinations of them when I get home.