CMOS checksum error on Abit AT7-Max2

[SafirXP]

After over a month of waiting I received the Abit AT7-Max2 motherboard. While starting up tt says "CMOS checksum error. Default settings loaded. Press F1 to continue, DEL to enter setup." Something like that.

BTW, it shows my AthlonXP 1800+ as 1150MHz and memory settings at 200MHz instead of 333MHz. Default settings I guess.

Anyways, I go to setup and change necessary things, choose Save & Exit, & the PC restarts. But then it doesn't show the BIOS anymore. The power & hdd lights are on, the cdrom drive lights flicker for a while, and nothing happens. I clear the CMOS using the jumper and things go back to the CMOS checksum error state again. What's wrong? I see that if I make any changes in the BIOS the PC does that (doesn't post).

Just to add, I've got the following stuff in my rig:
* 2 Maxtor 7200rpm drives
* Leadtek GF3 Ti200
* SB Audigy DE
* Kingston 2x 256MB PC2700
* Ricoh 20x burner
* Pioneer 16X DVD
* Dynalink Int Modem
* Surecome NIC

Oh yeah, one more thing. I updated the BIOS to see if it helps. Well nothing changed, still the same error! :S Any kind of help would be highly appreciated...

 

[Maximouse]

Someone else had that problem and I think they managed to get it going.

Try checking out the battery, maybe its weak or dead and the bios wont hold its settings properly.

You could also try taking the Motherboard out of the case and running it with just the cpu/hs, ram and video card to see if there are any grounds to the case or card conflicts.

Good Luck.
Al

 

[madsam]

when clearing the cmos, did you remember to shut the power off at the power supply? if there is no switch, unplug the power supply, and sometimes it is good to leave it in the ..clear cmos....position for 5-10 minutes...i don't know why.

also, next time the pc is booting with nothing on the screen, don't restart, or it will not post. this is a "feature" on these new boards. you will have to shut the power off, and then power back up again.

also, when you get into the bios, set the defaults for you cpu, and memory, and don't o/c just yet, and see if she boots and restarts, and shuts down ok, then go change settings a little at a time, so, you can narrow down what setting is not agreeing with your cpu, etc. if it is a setting problem at all.
i suggest this because i somwtimes get locked up on shutdown, and when i set the sissy settings in the bios, it seems to work ok, so, i think my problem is a setting.

and check your battery first like suggested above

 

[SafirXP]

I did all the above, didn't work. Now my box is at the store where I got the motherboard from. They're trying to figure out the problem & fix it (which I highly doubt they will). I'll check on them after an hour or so... this whole situation is so depressing. Waited such a long time for the board and now this!

 

[SafirXP]

Yay! Found & fixed the problem. My two Kingston PC2700 modules made the problem when put on slot 0 & 1. Works fine when I put it as slot 0 and/or 2/3. Guess my memory modules & the memory controller of this chipset has some stability/compatibility issues.

 

[Pla]

What you described that your DDR shows as 200 instead of 333 means you didn't change the FSB multiplier.
x3 is used for 200 and 100 FSB
x4 -> 266 and 133 FSB
x5 -> 333 and 166 FSB

If you put the FSB to 166 and multiplier to x3 you PCI will clock 166/3 = 55 MHz instead of 33 so many components (HDD, PCI cards, CDROM) won't work!

When booting the bios shows the DDR sppeed by the multiplier value - not the real clock spead.

When you buy a new board or when you clear the CMOS it will always say check-sum failed and will load the safest settings so you can boot and change them - this normal, infact this is what the jumper does - it just damages the data in CMOS so the check sum will fail...

If you have problems booting try using the memory at 266 not 333. Also don't set any timings on the memory - leave the defaults.
If it works at 266 then try 333 and be sure to lower the CPU mulitiplier and increase the FSB mulitiplier.
And if your CPU is locked that may be the reason why it doesn't boot at higher FSB...
Are you sure it's not locked?

 

[dvj81]

FSB multiplier = PCI divider ?

 

[the garynator]

fsb multiplier is 2, that gives you an fsb of twice what it is set at, ex. 133 fsb = 266 fsb, 166 fsb = 333 fsb. the divider he was speaking about is the pci divisor. this tells the system at which speed the pci bus is running. if you have an fsb of 100(200mhz ddr), and the divisor is 3, that gives you a 33mhz pci, which is what it is supposed to be. if you have an fsb of 133, than the divisor used to get the pci speed of 33 is 4. 166 = 5.

 

[dvj81]

Yep, that what I thought

 

[SafirXP]

Haven't tried overclocking yet. I'll get around to it early next month when I get the Volcano 7+ & do a mod job on the case!

 

[Pla]

yes - pci devider... (my brain was out...)

 

[SafirXP]

no offense intended : its still out! hee hee... why? becuz of this -> devisor

 

[Pla]

what are you talking about?
(Just kidding...)