I've been trying to make a build around that board recently but I'm having problems with the battery. I connected a 4.5v battery pack (3xAAA) to the 2-pin connector labelled "ext. batt" and it saved the settings for a few hours, then when I turned on the system a few days later the CMOS settings were gone and the batteries were completely depleted 🤯

I've tried reversing the orientation of the plug (I was connecting the positive wire to pin 1) but then the system complains the battery is dead so it doesn't look to be the cause.

Could the 2-pin "external battery" connector actually be a jumper that enables the use of an external battery (as opposed to the onboard battery that was previously soldered to the board), and the external battery is supposed to be connected somewhere else on the board? If then, where? 🤔

Sadly I haven't been able to find any information about the jumper settings for that board so it's been mostly trial and error so far.

I've found a thread that might be related to the same motherboard (unfortunately the pictures don't display anymore so it's hard to know for sure)