On rebooting I keep getting CMOS checksum error and can't get into Windows 95. NO, I DON'T WANT TO INSTALL WIN95 again and lose all my apps. Any ideas on how to fix the problem? Thanks

This is an error related to your memory. Install any lately?

It's probably a wrong setting in bios.
By the way, u can install win95 without loosing what u got on ur harddrive. Just install over your current version

I'm getting the same error. I think it's a memory problem but I didn't mess with memory lately. Any way of knowing what's wrong with the memory?

This problem is not caused by the installation of new memory.
Your on board cmos battery is flat.
It is a little lithium battery 3.6volt.
And can be bought from most PC shops.
PS. Make a note of your cmos settings before you install a new battery.

Thanks a lot! I just dunno how come the battery is flat, since I bought this computer 2 weeks ago... but anyway, I think replacing the battery is worth a try

Besides needing to provide more information, such as:

1. Have your bios settings changed?
2. Are your bios settings correct?
3. Have you tried replacing the CMOS battery (~$5)?

Basically, whats going on with your bios?

There are a few questions you must ask yourself and/or provide answers to in order for someone to fully understand your problem (the list above not being all inclusive). If you don't know the answers, then I suggest you: ask a friend who does, or bring it to the local puter store.

If your cmos battery keeps dying there are some reports of drain bugs on certain motherboards.

CMOS Checksum failure... After the CMOS values are saved, a checksum value is generated to provide error checking. If the previous value is different from the value currently read, this error message appears. Try to correct the problem by running the BIOS Setup program. I have: replaced the battery and ran the BIOS Setup progam. Every time I reboot, it goes back to the default settings. It continued even after upgrading the CMOS with the specified flash bios from the mother board's manufacturer. With "Troubleshooter" I get a "CMOS RAM Failure" message with a note: "Alarm failed". Looks like I'm going shopping for a new board tomorrow.

I recently downloaded and installed a program called "killcmos". The program was designed to intentionaly corupt the cmos checksum and enable you to reset your settings......PROBLEM is, it seems as though the computer will not recognize the "del" key and that is the only way I Know of to enter the setup.......anybody know of another way to into setup.......amibios 486 - AC4788707

I can't install MS-DOS 6.22 on my computer.
My computer is detecting that i don't have a hard drive or that my hard drive needs a special driver. It's a ll connected properly.
Can this be a CMOS problem

IM GETTING A CMOS CHECKSUM ERROR - DEFAULTS LOADED. I CAN'T EVEN GET INTO CMOS. RECENTLY I INSTALL A TAPE BACKUP (EAGLE96 EXABYTE). IN ADDITION, I INTALLED A VIDEO DRIVER AND MODEM DRIVER. WILL ANY OF THESE INSTALLATIONS CALL THAT ERROR. IT READS THE MEMORY THEN IT FREEZES WITH THAT ERROR AND ASKS TO PRESS F1 TO CONTINUE OR DEL FOR SETUP BUT ITS FROZEN AND I CAN'T GO ANYWHERE. PLEASE HELP!

I am getting the following messages when I turn on my PC:
CMOS CHECKSUM ERROR - DEFAULTS LOADED
CMOS BATTERY FAILED

Press F1 to continue

I press F1 and the PC continues on it's merry way. WIN95 starts and All applications work fine. The only symptom is that the board will not keep the correct date and time.

I have replaced the battery on the board, but this has not helped. I get the same message every time I boot.

Any ideas!! Thanks

How long does the battery last?
my cpu too gets the message cmos checksum error defaults loaded and i cant excess windows. could the problem be caused by the Ram in my motherboad?
PLEASE HELP!

Check out this bios manual at:
http://margo.student.utwente.nl/el/pc/bios/award45.zip
It is a little old(94) but has some good info.
I received the same error message today when I booted up a friends computer. It won't recognize the hard drive. Should I have the bios auto detect the hard drive or not, can't decide as I don't want to lose the info on the disk.

I get the same messages... CMOS Checksum error-Defaults loaded... I am not sure if it's the battery because i just bought the motherboard days ago and exchanged it the day afterwards and it's the same... Could it be something else besides the motherboard???...

I've got the same CMOS Checksum Error. In addition, neither bios or windows recognizes either of my CD drives. I swapped batteries with another computer, which still works fine and doesn't stop the error on the original computer. I've reset everything in bios. I've flashed the bios w/an update. Everything.

The only thing I did prior to this error was download and install MS DirectX 6.1. Improved multimedia my butt. Every time I tell myself, "don't download from MS" and everytime I say "oh, it won't hurt this one little time" and everytime I must either re-format my HD, reinstall all my drivers, or (for the first time (they're getting better)) buy a new MB. No wonder his name is bill (I'm the one always getting billed).

I guess I can sa y "me too!!!" I just bought an FIC VA-503A MB and upgraded an existing PC. Every time I start the machine, the "CMSOS checksum error - loading defaults" message comes up. I receive no message regarding the battery. I have replaced the battery, but it didn't make a difference. Every time I turn off the power, the CMOS settings are lost/replaced.

Since so many people have posted messages about this problem, perhaps someone knows the cure?

Very interesting discussion. I have identical error msg. Sure would like to know the fix.

My nieghbor has a 486 that is getting Failed CMOS checksum error message. The battery is a NICAD that is soldered to the motherboard. There are no pins for an external battery connection. What's the fix? The shop says they won't remove anything that is soldered to the motherboard.

Same routine...cmos checksum error-loading defaults. Replaced the battery, updated the bios. Same results. Machine runs fine otherwise. Any answers?

i've asked,& searched ,now I find this page all with the same error "cmos checksum error defaults loaded press F1 to continue. then every things fine (maybe slow though) and no one has a real answer. i'll bet if every body threw in $1 we'd have an answer and one guy would be a million aire..HELP!!!!!!(is mine going to finally freeze as some others have??)

it would be interesting to know the brand of MB and BIOS in these computers? Could it be a company/brand wide problem?

After some searching, the only other thing I have to add is dealing with the RTC (real time clock). The following excerpt is obviously aimed toward a particular brand, but the information on the RTC could prove accurate (and indicates the need to replace the motherboard - sorry guys :( )

*********************************

If system displays CMOS BATTERY STATE LOW or if the system displays CMOS CHECKSUM ERROR then most likely the CMOS battery or R.T.C chip (Real Time Clock) is running low. On the new motherboards we have the R.T.C chip is soldered on board and therefore it is not replacable. If the problem like this occurs with new motherboard then you will need to replace the motherboard. Most of the early 486 motherboards had the CMOS battery and if the CMOS battery ran low on those boards we could send the customer external battery.

NOTE: This problem will be mainly seen on following motherboards: MBD-P5RB/SB/CB/MB/YB/ZB. There will be a workaround on this problem. Basically we've been using R.T.C chip made by ODIN so far and they seem to be failing only after short time of use, the workaround is that new motherboards will have R.T.C chip made by DALLAS which should solve this problem.

I am absolutely amazed at just how many others have exactly the same problem as me. I have a TMC TI5VG+ Motherboard with an AWARD BIOS; the board has been replaced with another which has developed the same problem. It doesn't occur at every boot-up, but sometimes every couple of days. I also would dearly love to find a solution.

the asus motherboards are known for draining the battery, it took me a while but i found out that on there needs to be a jumper on the atx pins. they are over where the speaker, hd led, etc. plug in. replace the battery and jump the pins and sit back and see what happens.

same here, cmos checksum error press F1 to continue, windows loads all is fine, apart from when i have to start the computer about 19 times at the beggining, so is it my battery, i noticed the windows clock doesnt keep time...

anyone who has the ti5vg+ motherboard , please contact me , i may be able to help .

same here, cmos checksum error press F1 to continue, windows loads all is fine,only problem clock starts on wrong date/ -time ok,
its a old 1996 pentium 100,award bios which i brought at auction house- have seen program to trash-kill cmos is this worth running?
or just buy new m-board or then again just press F1?

I have been experiencing a problem with my PC. I get a "cmos checksum error - defaults loaded" message during boot-up after auto-detection of my drives. I am able to continue by pressing F1, but very often a variety of settings have been changed in the BIOS, sometimes including the date and time. This will happen sometimes three times a day and then not again for three days. I have tried changing the battery, resetting the cmos, I am now on the third motherboard from my supplier, but still it crops up.

For what it's worth I have a TMC TI5VG+ Motherboard, AMD K6-2 350 Mhz Processor, 128 Mb SDRAM, S3 Trio32/64 PCI 2D Graphics Card, Matrox M3D 3D PCI Graphics Card, ES688 AudioDrive Sound Card (ISA), Rockwell HCF 56k Speakerphone PCI Modem, Seagate 2.5 Gb Hard Disk, Maxtor 20.4 Gb Hard Disk, Mitsumi FX320M2 CD-ROM Drive, Iomega Zip100 Drive all housed within an Enlight EN-7230 Case with a DTK 230W Switching Power Supply. The BIOS is Award Modular BIOS v4.51PG and I am using Windows 98 v4.10.98.

If anyone has an identical problem and any of the components above in common then I would be interested to know.

Having trawled the internet for possible solutions I discover there is a multitude of people out there with similar problems. Any additional light that you can shed on this very annoying problem would be most appreciated.

I was trying to make a Windows95 boot disk when I got the " checksum error ". I lost access to all my drives. I went into the BIOS and found that the A: was checked " uninstalled ". I changed it to 3 1/2 1.44MB and it worked. I lookes at the Master Drive and it was also uninstalled. I am talking to Seagate about the settings for the HD.

drew

I am getting a CMOS CHECKSUM ERROR and KEYBOARD FAILURE! I can't do anything and am completely stuck. I just bought all the components and had the machine up and running (Win 98 SE). Then I installed the drivers for my ATI Rage Fury Maxx and after the computer booted up all I got was a black screen with an hourglass. After 15 minutes of looking at an hourglass, I rebooted and got the same thing. I decided to clear the RTC data on my FIC SD11 motherboard by moving the jumper to the "clear" position. Now all I get is CMOS CHECKSUM ERROR and ERROR and KEYBOARD FAILURE. I can't even get into BIOS now. HELP!!!

Well this system isn't a new one (386) but it
gets the same xcmos checksum error at boot. I
checked out the battery voltage and it is a
little low yet the machine seems to keep the
date and time OK. Since the MotherBoard does
have an external battery connector (I hope
there's no jumpers involved in hooking up an
external batter) then I'm going to replace it
anyways. When it does boot and give me the
error, I don't have access to my hard drive
after starting from a floppy. The hard
drives settings still seem to be correct in
the BIOS however when I enter the setup. I
see no indication of an automatic setting.

I guess my biggest question at this point,
(since there is lots of usefull advise here)
would be.. Is it OK to cut the old soldered
on battery off the motherboard? It seem

My setup is:
P6BX-A+ Motherboard
P2-233 Processor
128MB pc66 ram
VGA adapter
Floppy disk

When I power on the system it reports:
-CPU 133mhz
-memory 131xxxx don't remember the exact number, but its correct
-BIOS CHECKSUM ERROR

F1 to continue or DEL to enter setup

I go into the BIOS setup and set it to optimum, and make sure the cpu speed is correct at 233mhz. Save and exit.
Nothing happens when I power on the system again. If I power off the system, remove the power cord and reseat the CPU I get the result as listed above all over again. This is a new motherboard out of the box.

Help!!! What can I do to solve this problem.

I got the same error on a new abit board and I'm just making a reply because a lot of you keep saying to check the bios settings. One thing that I could not do due to this error was getting into the BIOS settings. The board booted up, showed the video card splash, then the error, then nothing. Never a chance to get in anywhere. I just got the board replaced with a new one, don't know what was wrong.

CMOS checksum error appears to come from
a dead battery. I am looking for a
replacement for the ODIN battery. Repair
guy said to look for the DALLAS battery to
replace it. Anybody know anyone who has
one? Call 305-653-1679 now to make a fast
$10 finders fee.

mine is a 486dx2/66 machine. I get a CMOS
Checksum Failure, CMOS display type mismatch,
run setup utility press f1 to continue. When
I run the IDE setup which auto detects my HD
and save changes and exit everything is
fine... until I turn OFF the computer and try
to turn it back on. the changes are gone and
it gives me those errors again. I replaced
the battery now it only errors about 8 out of
10 times! I had noticed a while back that the
date was not keeping up. seemed as if I didnt
have my computer on for days that the date
was way behind the actual one. Any clues? I
know this is similar to what everyone else is
saying but the error is slightly differen

believe it or not I found out the problem
with the CMOS errors for my machine! turned
out it WAS the RTC chip. apparently the
computer was not y2k compliant and I had to
fix the date in DOS before it would start
saving changes in the BIOS and boot properly.
I dont know what version of Windows everyone
above is using but if it has DOS 5.0 and
above go to your dos prompt and type DATE.
then reenter the date even IF it shows
correct. just pressing enter wont work. Then
change it in windows too. hope this might
he

To cut a long story short, I am not the only one who uses my PC,
and what was happening was that sometimes when my wife or my son were using
it, at shut down, when they were prompted on the screen that "it was now
safe to turn off your computer" they were turning it off at the mains wall
socket, and not pressing the on/off button on the PC, or even letting it
time out for the couple of seconds needed and allowing it to shut itself
down automatically, as I tend to do. As it is around about this stage
during the shut down procedure that the checksum is taken by the PC for
subsequent comparison at the next boot-up sequence; depending on the timing
of the switch-off at the mains wall socket, very often errors will be
introduced into the checksum, with the resultant error message, and all that
goes with that, appearing at the next boot-up.

Now that we are all switching off correctly, we are getting no further
problems. I hope this will be of assistance to you, although if your
motherboard does not use the same power on/off signal arrangement then I
don't suppose yours could be the same fault. Let me know how you get on, I
would be interested to hear.
Regards.

I have the same problem only with two boards. I had the prob with one board and then tried the other. Same thing. So I completley installed a new bios. Same thing on both boards. Try changing your case. Not just the power supply get a new case thats what im gona do.

all the information on the Odin/Dallas RTC issues
http://www.resource800.com/dalsemi.html
they're about $30 on this site
also, RadioShack has a couple of these batteries for around $22

Well, to add my voice to the many, I've got a Transcend TS-AVE3 mobo, brand new, had it working for a couple of weeks. Yesterday I took it apart to install a processor upgrade, and nopw I'mgetting "CMOS checksum error - defaults loaded, press F1 to continue, DEL to enter setup" except that my keyboard doesn't respond. So it just sits there and I end up turning it off. I tried a different keyboard AND a different battery, with no result. The wierd thing is that the keyboard and mouse failed on the boot BEFORE I got the CMOS checksum error. I booted Windows, and got "Windows did not detect a mouse blah blah blah" and my keyboard wouldn'twork either. So I did a hard reboot, and got the CMOS error.

There is one thing I thought of... this mobo has a jumper labled VIO that has three settings: 3.4, 3.5, and 3.6. I accidentally put it on the 3.6 setting instead of the default, 3.4, and booted. I don't know what effect two tenths of a volt could have, and I'm sure it's not the CPUVCORE, cos this board runs Celerons, and they run at something like 2.6. I dunno... It's a puzzel. If anyone figures anything else out, let me know!!! :)

Me, Paganini

Okay, since everyone here seems to be convinced their problem is a battery issue, let me see if I can throw a curve into this... Multiple machines, all identical hardware configuration... Abit BF6/Celeron 466... All machines observe this problem immediately after building. If drives are imaged with a win98 software image, everything is just fine. If imaged with a particular win2k image, all systems fail Checksum at startup/reboot... I can tell it is something to do with the software configuration, as if I reset values in BIOS (namely softmenu CPU speed), I do not get this error if I shutdown and restart immediately, before the OS boots. This is not a battery issue, my only conclusion is that this is caused by some driver combination/ low-level BIOS manipulation on the part of Windows 2000. If anyone has any experience with this oddity, please send me an e-mail. I would greatly appreciate!!

Why not continue the mystery?...... I get the CMOS Checksum error F1 clears it and then everything runs normally. It's an older 1996 Pentium running Win95 with Award BIOS. I tried the suggestion about changing the date at DOS prompt, but to no avail. Here's the kicker guys..... if I change my date to 31DEC99 the problem disappears. Its only once it turns over to 2000 that the error occurs. Also, the system date has always been correct, so it isn't a batter problem (at least not in my case) and upgrading the BIOS didn't do it either. Since this occured the first time last January 1st, I'm going with a Y2K non-compliant idea. Let's not quit till we find the problemo!
Thanks for sharing!

Same "CMOS checksum" problem here, brand new FIC VA-503+ MB ran fine for 3 weeks, NO changes were made and this started happening. Another site suggested this was caused by either a failed BIOS flash or the AntiCMOS.A Virus but no BIOS flash was performed and I read a description of the AntiCMOS.A virus and the symptoms don't match up exactly.
Some techies gotta know what this problem is!

I am experiencing the same proble whenever my computer date is changed from 1999 to 2000. If I change the BIOS date to any date prior to 31DEC1999, the problem disappears. So the problem is not battery but P2K. I tried to update the PC date at DOS prompt, it didn't work either. Does anybody know a utility that reads/writes the CMOS memory ? Why the date affects the CMOS checksum ? why does the BIOS put the date into the checksum calculation?

Actually I don't beleive it has anything to do with OS, well in my case anyway, nor is it the battery (changed that twice now), nor is it the case or power supply (crazy idea whoever stated that (but I did just change cases anyway :B)) As far as OS, I originally installed Linux Red Hat 6.2, then Linux Mandrake 7, then Windows 98, then Windows 2K, then Unix BSD, then OS2, then Win 95, then NT, always got the same problem, so common it can't be the OS.
After doing all that I kicked the case real hard with a steel toed work boot, that didn't seem to help either.

So I'm out of ideas.

Anyone try a different video card?

I was having some strange problems with my
system - when I shut down the system, the
screen turned into a narrow horizontal stripe
accross the middle of my monitor - The system
would freeze intermittantly - And finally,
the system did not appear to be able to
restart in MSODS mode (I later found that it
actually was restarting in MS-DOS mode, it's
just that the screen never changed from
win95 to dos. I typed exit and pressed enter, powered the monitor off / on then it came back to a "live" windows screen...)

Anyhow, all these problems led me to believe
that maybe my ancient 250W AT power supply
wasn't strong enough for my system (FIC
VA503+ motherboard JE439 bios, 64MB ram, 4MB
Diamond Stealth 2 S220 PCI video card) so I
moved my system over to a a new case with a
standard PS2 type AT power supply (same
amount of juice)...

The problems stayed - as expected...

I swapped out the power supply with a 250W
ATX... Now I get the CMOS CHECKSUM FAILURE.
I loaded the defaults and continued on...

When I selected shutdown, the system shut
itself off but after about 10 seconds it
powered back up to a blank screen with a
blinking cursor - No Post, No Ram test - just
a blinking cursor.

To resolve the CMOS CHECKSUM ERROR I tried
replacing the battery (didn't help), and
swapping out the 250W ATX with a 300W ATX
Power Supply (also didn't help).

At about this point in my story I stumbled
upon this forum and read the FAQ referenced
by reply number 40. After reading this FAQ,
I'm thinking that it's my video card that's
freaking out my system...

Anyhow, I'm going to see if there are any
firmware updates for my current video card -
if not, I'm going to try a different video
card. I'll post my results tommorow...

Later - Walter