Spectra S1+ Not Charging Battery

Had another unit to mess with. This will not charge it’s battery, upon power on with the charger/adapter, the battery icon blinks empty continuously for abit, before it gives up trying to charge the battery.

Turning the unit on without the adapter, the LCD will come up for 1 sec, then shutoff.

Took it apart, battery looked fine, voltage measured ~11.1V and stable (I thought it was dropping out when the pump was commanded to run), pulling the pump and solenoid connector off and trying to run the unit with the battery, exact same behaviour (shut itself off after 1 sec).

I then turned my attention to figuring out how the microcontroller on board measures battery voltage, found a resistor divider and a little output capacitor just to the right of the microcontroller (R36, R38 and C35R).

Measuring the top (input from battery) and turning on the unit from the front panel (fiddly yeah), I only measured ~8V (when it should be ~11V), somehow full battery voltage was not making it through. The input is not applied to the divider all the time, only when the micro commands the unit on, does input voltage appear thru the action of Q12, Q11 and Q9.

Probing around Q12, Q11 and Q9, I couldn’t find anything wrong with them. I ran a jumper from battery voltage to the input of the voltage divider and verified the unit works as it should, next I shifted the jumper to the input of Q11 and once again verified that the unit works (will accept charge, will turn on and stay on with battery power).

This was when I realised there might be some broken trace or via from battery voltage to Q11.

Flipped the PCB around and removed the LCD+plastic support.

Looks like some fluid damage under the Down switch.

I removed the switch, cleaned the mess up and found that a via leading to the other side had broken, there’s no good way to patch that via (since it’s so small) and I opted to keep the jumper on the component side. Didn’t take a picture of the completed patch, but it looked like the original jumper I put on, except tucked neatly away and the battery voltage tapped from closer to the battery connector (after the ferrite bead from the charging section).

Reinstalled everything, charged the battery and tested it out, I can confirm everything is working as it should.