Unit: 6680
Fault: grounded and no response to charger
Procedure: first is to trace shorted or grounded parts and remove them.

for this unit. P.a is shorted and the positive line of charging interface is grounded.

here are the pics:



this is the procedure i did
bale yung fuse hidi ko kinabit dun sa isang dapat na pinaghinangan nya na tungo sa charging pin interface. kasi nga grounded na or connected na sa ground kaya naka linsad ito
parang ito ang posisyon ng fuse

Finish product