Desktop motherboard CMOS battery replacement

Some days ago (two to three weeks ago perhaps), my desktop PC’s clock was losing time, a sign of CMOS battery dying. A few days later the BIOS startup screen started showing messages of corrupted CMOS but still allowed me to boot up the machine. Three or four days after that the PC did not even show the BIOS startup screen.

I found out that the battery to be replaced is CR 2032. Looked around for it in Puttaparthi as my regular computer service person was temporarily not available. Was directed to Oblesh watch repair guy, a friendly watch repairer who I have interacted with many times. Oblesh’s son was manning the shop and gave me a CR 2032 H battery of Maxell for Rs. 50/-. This was perhaps three or four days ago.

I think this is the first time I am replacing the CMOS battery in my desktop PC. So, on my alternate comp. (DELL Mini Laptop), I tried to search for some info. on it. Here’s a short video, How to Replace CMOS Battery in a Desktop Computer’s Motherboard,, 1 min. 54 secs, which demonstrates how to use a screwdriver’s flat edge to push against the clip and into the battery circular rim/edge to pop it out.

Putting in the new battery is simple. Just push it in the slot. The clip should automatically lock it in place.

Following the above instructions I replaced the old battery with the new one. But my PC did not show the BIOS screen. So changing the battery did not solve the problem.

Read up some articles on those who faced similar problems. Clearing the RTC RAM (CMOS battery powered memory) was a suggested step. The ASUS M2NPV-VM manual explains the procedure. Essentially the battery has to be removed, then the RTC RAM jumper position has to be changed for 5 to 10 seconds, after which the jumper has to be put back in its orignal position. Then the battery has to be put back in. That finishes the clearing RTC RAM (CMOS battery powered memory) procedure.

Followed these instructions. Struggled to remove the RTC RAM jumper with my fingers alone. Finally used a screwdriver head to hold one side of the jumper and succeeded in prising it out. Another jumper nearby was creating some interference. So I removed that jumper too. Putting the jumpers back on was quite easy.

However, even that did not solve the problem! The PC processor fan would spin but that’s it. No beep from motherboard and no BIOS startup screen was being shown!

Read articles on the issue (using Google search) and saw some videos too. One suggestion was to remove the memory RAM sticks and check that the computer beeps on power on with no RAM. I tried it and I did get the beeps.

Plugged the RAM sticks back in and powered on the computer. Once again no beep and no BIOS startup screen.

Thought that the CR 2032 H battery may be the problem as the earlier (dead) battery was CR 2032 plain (no H). Was lucky to find a CR 2032 plain battery with another person in Puttaparthi for Rs. 20/- only. It stated Maxell on the packing but after I had come home and removed the battery from the packing, I saw that the battery itself states Maxtel instead of Maxell! So I seem to have got a Chinese low quality brand. Anyway, I decided to try it out. Putting this Maxtel battery in the motherboard did not solve the problem! Still no beep and no BIOS startup screen.

Eventually I thought I should reduce the RAM sticks on the motherboard. Reduced it from 3 sticks to 2 (each 1 GB RAM) with the 2 GB RAM stick removed. Now the computer powered up and booted OK! Success! What a relief!

Shutdown the computer. Now I added the 2 GB RAM stick. I think I may not have placed this 2 GB RAM stick properly earlier. Maybe that’s what tripped everything up. This time around I seem to have placed it correctly as when I powered on the computer, it booted and picked up the additional RAM (total 4 GB RAM)!

So problem was finally solved. But Oblesh told me today when I met him and spoke about the CR 2032 H and CR 2032 plain label batteries, as well as the Maxtel branded battery, that 2032 H should also work with the PC. He also said that the Maxtel brand is a “Chinese” brand and that it will not last long.

I guess I will continue with the Maxtel brand battery for now. I have the CR 2032 H, Maxell battery as spare.


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