Gameboy SP charge problem.

[Hamburglar]

Got a AGS-101 backlit model SP.

Works fine, however it won't charge the internal Li-Ion battery.

Got a new battery, was charged, worked for a while, now of course the battery is super low- I tried another known good battery won't charge that one either.
Ac Adapter good, when I plug it in the charge indicator lights for a brief second then turns off, as if the battery was fully charged, which is not the case.

I see 2 fuses inside, they are good. Don't see any other.

Just wondering if anyone knows anything about this problem, trying to troubleshoot a SMD circuit without a schematic is not fun...

[porchy]

hi, i recently had this problem after digging my SP out of the loft. I left it on charge for an hour or so but the light just kept going off after a second.
i eventually got around it by holding down the backlight button while plugging the charger in. not sure if this actually made any difference but it worked for me