Gameboy Advance SP Won't Charge

My Gameboy Advance SP has a battery charging problem.
Unlike GBA SP Will not charge even with new battery | GBAtemp.net - The Independent Video Game Community where 'it flashes the charging light on then off' my GBAsp does not show any life at all when I plug in a charger.

I bought a new battery and the battery does not charge on my AGS-101 Gameboy.
I've looked online but I can't see anybody talking about this specific issue.

• ✅ Both fuses F1 and F2 show 0 Ohm continuity
• ✅ EM8 shows continuity with about 0.1 Ohms on both sides
• ✅ The Gameboy plays and turns on with a charged battery in it, and the battery holds a charge when I charge it with an external power source
• As soon as I plug in the Gameboy to power, it stops working. Unplugging it does not turn it back on, only unplugging and flipping the switch off/on fixes it
• With the charger plugged in, there are 0.7 volts present at the battery terminals in the Gameboy. It's as if it never tries to charge the battery.
  
• No matter if there is a battery present in the system, or the position of the on/off switch, it pulls 30ma consistently when plugged in.

The charging light never comes on, meaning it never turns yellow or green. But the low-power light does come on. Pressing the charger into the charge port in weird ways also does nothing, and I can see 5 volts on various points on the board near the charger which lead me to believe this is not to do with the charging port.

Anyone have any ideas? This GBAsp with this charger used to work, there's no signs of corrosion on the board. Are there more things I can test to see if they are broken like fuses or diodes? Traces that should show continuity, or traces that should not?

Thanks!

 

I have checked the charging port.

The on/off switch is dirty but I can shake this GBAsp and tap/hit it with the palm of my hand and it won't turn off. Immediately when I plug it, in the power goes off. And it won't turn back on while the charger is plugged in, no matter how much I flip the on/off switch.

 

And I have opened it up, hence how I was able to measure component values. I don't see any corrosion anywhere.
F1 and F2 are fuses for the battery and for the charger (from what I know). Both show 0 ohms so both are good. EM8 is an inductor on the backside (side with buttons) that people say has to do with the charging circuit.

 

To tack on, I have verified with a multimeter that the switch does work. In one direction legs 1-3 are common, in the other direction legs 2-4 are common. (2 and 3 soldered to the same trace)

This board is a C/AGC-CPU-01 model and I noticed the audio ic getting warm. Is that normal? It pays music just fine.