Jump to content


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.

Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.


CMOS Settings being forgotten? Is this a bad CMOS battery?

  • Please log in to reply
2 replies to this topic

#1 1001help


  • Members
  • 50 posts
  • Local time:02:18 PM

Posted 23 January 2015 - 12:00 AM

hi guys. I was having a problem which I posted about


here: http://www.bleepingcomputer.com/forums/t/559889/computer-wont-boot-just-a-loud-fan-and-a-blank-screen/


my computer wasn't booting the fan would just be really loud and nothing would ever come on the screen. so I tried to troubleshoot it and find out what was wrong. two of the things i did were 1.) reset the CMOS settings by removing the CMOS battery, and 2.) I reseated everything including the ram. well, to make a long story short, I thought it was one of the ram mods that was broken but someone here suggested it may be the CMOS battery and that I should change that first and see if it fixed the problem since it would be cheaper then getting a new ram mod. well, I got a new CMOS battery and changed it and put the ram mod back in and now my computer works again and boots just fine but theres still a problem.


if I turn off my computer and flip the switch on the outlet strip I have it plugged into, it eventually forgets the cmos settings that I saved and so when I turn the computer back on, it will say "diskette error" or something like that and the time and date will change. I know how to fix both but when ever I do, it just forgets the saved settings all over again every time I shut the computer off.


does this mean the new CMOS battery I installed is bad? I ordered a 2 pack off of amazon and it was new in the package, but after this started happening, I looked on the package to see if i could tell how old the batteries were and it says the copyright is 2012 so is that the problem? the battery is just bad? or can it be something else?



BC AdBot (Login to Remove)


#2 Platypus


  • Global Moderator
  • 15,213 posts
  • Gender:Male
  • Location:Australia
  • Local time:06:18 AM

Posted 23 January 2015 - 01:35 AM

First guess would be to question the new battery/s. It's not unusual for stock to be old and have gone flat.


Also make sure the contacts in the battery holder are nice and shiny without any tarnish on the metal surface. Batteries can have an oily protective coating and need a good rub over with a clean cloth before fitting. If there's a "clear CMOS" jumper fitted to the mainboard, make sure it hasn't come loose or fallen off. The "non-CLR" position of the jumper passes the battery supply in the common design.


Unfortunately, the mainboard can develop a fault preventing the battery power from reaching the CMOS chip. It can be a component fault, generally a diode, or a copper track failure, unfortunately usually inside the multi-layer board. It's not a common failure, but I have seen it once or twice.

Edited by Platypus, 23 January 2015 - 01:36 AM.

Top 5 things that never get done:


#3 1001help

  • Topic Starter

  • Members
  • 50 posts
  • Local time:02:18 PM

Posted 23 January 2015 - 05:58 PM

ok. I'll check out and try all that in a bit. thanks for the tips I'll let you know what happens.

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users