Hi there, does anyone happen to know the exact type of the RTC/CMOS battery for DEC740 / DEC750 (Netboard A10 Gen3)?
Probably a CR2032 but take a look. It is etched on it for sure.
It looks like an LR44 - not certain though.
The problem is that now — about two years after buying the new DEC740 — the battery has completely disintegrated ... black pieces of material, with only the top metal cap remaining. The metal battery holder on the PCB has also partially detached on one side.
I've never seen anything like this in hardware before ... I'm asking myself what could have caused the battery to degrade like this after just two years ... I can't explain it.
Send a picture
Confirming LR44, I changed one as well.
�Few pictures
#2
Battery LR44 ... well the remaining part
Your main board definitely calls for someone with a soldering iron and the matching skills.
as a current owner. wow that is kinda crazy
Quote from: DEC740airp414user on June 02, 2026, 01:08:25 PMwow that is kinda crazy
Crazy - indeed.
There must have been something really weird going on with the LR44 - leakage, short circuit or something of that nature, which resulted in disintegration / bulging, pulling the metal bracket off the PCB ... just speculating.
Good news is that soldering the bracket worked and for now the DEC740 seems to work fine.
Just found your post and I've just encountered the same problem with my DEC2750 (see https://forum.opnsense.org/index.php?topic=52666.msg272506;topicseen#msg272506)
How did you manage to get yours soldered back on? Where the pads on the board still usable?
Quote from: Scandiravian on August 08, 2026, 12:58:40 PMWhere the pads on the board still usable?
I guess these two posts say it all :
- https://forum.opnsense.org/index.php?topic=52036.msg267980#msg267980
- https://forum.opnsense.org/index.php?topic=52036.msg267981#msg267981
Seems to be easy fixable, but I don't know about your issue, which seems worse : https://forum.opnsense.org/index.php?topic=52666.msg272506#msg272506 :(
Good luck! :)
When you replace the battery, use an SR44 / 357 silver oxide rather than the alkaline LR44. They are less likely to leak and last much longer. I found this decades ago in my HP32SII (still in use, incidentally).