I recently replaced the CMOS battery on my intel 11th gen board (which I am using in standalone mode) I suspect I may damaged something on the board by using the wrong replacement battery but I am not sure about that.
Since the swap, it doesn’t retain the BIOS settings anymore, which is annoying because I am using it as a home server right now. To be sure, I replaced it again with a rechargeable 3V ML1220 battery. However, this did not solve the issue. Furthermore, I accidentally broke part of the CMOS battery holder and I believe there is slight discoloration at the negative (-) contact point on the board/holder. The voltage of the CMOS battery is >3V currently.
At this point, I am not quite sure whether the BIOS settings retention issue is related to something that I have damaged on the board or it may just be the broken socket that results in a loose connection. Has anybody any idea how I could troubleshoot this definitively, for example using a multimeter?
Unfortunately I am not confident enough with electronics to figure this out myself.
What was the 'wrong battery". If we knew, we could probably make a judgement if it might have broken anything or not.
As you have found, the most likely thing to break is the plastic battery holder.
Unfortunately, i don’t think there is anything that tells us if the cmos battery is ok/connected ok. Or not.
Not a lot of help now, but FW replace the battery for you, even after one year, due to an issue they have with the board.
I thought that 11th gen boards had to have some voltage in the CMOS battery in order to post. Maybe it is different if it knows it is in standalone mode?
Loosing the settings and time is a decent indicator it is not making contact in the holder. Lots of people break the fragile battery connector. Some good kapton tape or even good electrical tape is an ok fix too as long as it is making contact with both pins of the battery holder.
Only way to check that would be to probe a trace or two on the mainboard to check if voltage is going on after the battery connector. I do need to put in for a battery replacement myself for my 11th gen. Debating if I should do the rework solution or just replacing the same rechargable cell. Haven’t soldered something that tiny in years.
Hey again, thanks for replying so quickly! Well I guess must be Occam’s razor again. What strikes me as odd however is that I actually can measure a voltage of >3V between the two contacts once the battery is in. I even tried to shake it a couple of times with the same result. I’ll try to fix it with a touch of hot glue then to secure it mechanically, insulating tape alone won’t do the job I think. The annoying thing is that only 1/4 or the holder is broken of so it is pushed out a bit by the negative contact/the other side of the holder.
I just tried to disconnect and reconnect it from AC a couple of times and it retained the BIOS settings. I connected it to a time switch and have it powered off for the night an see how it goes.
Hey, small update. I’ve managed to secure the RTC battery a bit more tightly, had it detached from mains overnight and so far it worked out fine. I guess the issue was that every time I modified the BIOS, I had to carry the board over to my monitor and back to its original place. During this process, the battery must have come loose every time I guess.