Help Coms Checksum Error??

[Yamboo29]

what exactly does COMS checksum error mean? I ttry to go into
the bios to set everything the deafults, and then the computer
resets, but Nothing on screen, and i get FF on motherboard. I tried reverting back to the orginal Bios, and i can set some things. all i have been trying to do is add memory. i cleared the cmos. Please Help befre the motherboard be comes toasts totually! Thanks

P.s. the MB is a Epox EP-8RDA6+PRO

[Aedan]

If you get the message saying "CMOS Checksum error" it means either the CMOS battery is going flat (There's a small battery on the motherboard), that the clear CMOS jumper is in the wrong place (or you've just moved it) or the CMOS RAM has failed.

[Yamboo29]

well i have been removing the battery, and clearing the cmos alot
lately because i've been trying to get another stick of 1GB pc2700 memory to work. can taking the battery out or clearing the cmos
too much, cause this?

[Yamboo29]

p.s. what exactly is the cmos ram? is there any way to fix this before it dies?

[Daniel ~]

Make sure off the following:
1. the battery is correctly installed
2. Your jumper is in the correct position on the pins (easy to get wrong!)
look for any connection near by you may have dislodged....often best to look by feel.

3. pick up a battery and see it replacing it helps.

4. stay tuned for better advice from more knowledgeable people.":O}

[Yamboo29]

i did all that. the system will be find for a while, and then all of a sudden the the mouse and keyboard will lock up in windows. if i press the reset button, the monitor wont come back on, and i'll get FF on motherboard. if i put another memory stick in, hold insert while powering on, then the monitor will come back on and system will boot. i havent been getting the cmos checksum error anymore. its just these sudden lock ups. everything was find until i tried to add more memory yesterday. and know none of the memory slots are dead, because i have memory from another computer in it. also, i know the new memory isnt bad, because it works in another computer. I reflash the bios tonight to see if that helps anything.

[Yamboo29]

ok now it appears it is either a short in the motherboard, or a bad power supply. (just a note.. i did just replace the power supply last month, cause I was receiving shocks and had that power tested, and it tested dead) The power Supply i have in it now is a Chiefmax 550 watt with dual fans. I also check the motherboard to make sure it wasn't shorting out. now whenever i go to boot i get the FF (sometimes i'll get an F2) error code with nothing on the screen, and i'll have to keep pressing the reset button quickly until it saids something other than FF then it will boot. once it get into windows xp, it'll either freeze up or it'll be find until after I get done playing a game.it mainly does it when I reboot.

one other thing, the power light and hardrive light are both on when it freezes up.

[Aedan]

Originally Posted by Yamboo29

p.s. what exactly is the cmos ram? is there any way to fix this before it dies?

The CMOS RAM is about 256 to 512 bytes (1/4 to 1/2 Kbyte) that's used to store parameters for the motherboard operation. It stores things like the boot order, the hard disk types, memory settings - pretty much the things you can set when you go into the BIOS. It's usually part of chipset, so it's not replaceable should it fail.

[Yamboo29]

ok, the board locks up/freezes after i play games. if i push the reset button, i get nothing on the screen, and FF on the motherboard. if i turn the switch on the back of the supply off for a mintue or two, it turns on and boots up no problem. would this be a memory problem or power supply problem? I'm thinking memory problem because sometimes it will beep two short beeps, and then a constant beep. but I have tried another pc2700 1gb memory stick which wont work by itself, and if i use it with the stick thats in here now it will post, but it will freeze if i press any keys. if i dont press any keys, it will post and then freeze. I have tried both of these memory sticks (seperate and togather) in another computer, and they both work fine with no problems.

[Wolf2000me]

Hey,

The 8RDA6+ Pro is very picky when it comes to memory. I've had similar issues with my board using twinmos twister pc3200 memory. I later found out that it wasn't fully compatible with the board. I then used corsair twinx which solved all of those problems.

Using a CPU which has an FSB of 133 default you are putting a lot more strain on your memory unless you did the L12 mod.

I suspect your memory to be incompatiblish. Not uncommon for this board. Set your timings to 2.5-3-3-11.
Your memory size is also too big for the memory controller and it won't get better running out of synch.

Never ever change FSB with incompatible memory. You risk corrupting your BIOS firmware. Check it with memtest.
Ideally, the memory controller works best with 256mb sticks, however 512mb sticks are okay, slightly limiting you FSB-wise. Using sticks of 1024Mb is simply pushing your luck.

I suggest finding a dual channel pc3200 kit of 2x512Mb on the second hand market.

[Yamboo29]

Originally Posted by Wolf2000me

Hey,

The 8RDA6+ Pro is very picky when it comes to memory. I've had similar issues with my board using twinmos twister pc3200 memory. I later found out that it wasn't fully compatible with the board. I then used corsair twinx which solved all of those problems.

Using a CPU which has an FSB of 133 default you are putting a lot more strain on your memory unless you did the L12 mod.

I suspect your memory to be incompatiblish. Not uncommon for this board. Set your timings to 2.5-3-3-11.
Your memory size is also too big for the memory controller and it won't get better running out of synch.

Never ever change FSB with incompatible memory. You risk corrupting your BIOS firmware. Check it with memtest.
Ideally, the memory controller works best with 256mb sticks, however 512mb sticks are okay, slightly limiting you FSB-wise. Using sticks of 1024Mb is simply pushing your luck.

I suggest finding a dual channel pc3200 kit of 2x512Mb on the second hand market.

How can you say the memory size i am using is too big for the memory controller? is the memory controller not caple of handing 1024Mb in each slot? the board was built to handle 3GB. that's what i want.

[Gizmo]

There have been numerous issues reported all over the web by people with NF2 mobos (not just the 8rda6, but pretty much ALL mobos using the NF2 chipset) and running 1 GiB memory sticks. EPoX used to have a list of recommended memory types to be used with their boards, and nVidia had a list of recommended memory types to be used with the NF2 chipset.

Be aware also that Windows by default will only let you use 2 GiB of the 3 GiB of memory, even if you get it to work. There is a workaround to allow you to use the 3 GiB, but it won't do it out of the box.