Chosen Solution
I have a Galaxy tab 7.0 (T210) and it looks almost new, not even a scratch on the digitizer! She told me that she almost never used it. Anyway, the tablet seems to not charge the battery at all. The battery reads 2.86 volts and was last chaged 100% around 4 days ago. I find it very strange that the battery can go at so low voltage, maybe something draining it intensively. or the internal resistance of the battery. The battery voltage does not change at all when I plug in the usb. I tested the usb port, and I can read my 5volt on the board, so the usb are not the problem here. Then I unplugged the battery and saw random voltages between 1.5 to 3 volts on the battery connector on the pcb while the usb are plugged, wich means some current are travelling towards it. But something are blocking the charging process. So my guess might be a defective charging ic. But im not sure at all about it. Can you help me, thanks
Did you check the charge port pins to the motherboard under a microscope? They may be loose. Push on them a little with a pair of straight tweezers to see if they move. Also, look internally into the micro USB connection (where you plug in the charger cable), a pin may be bent.
Thanks Frank, But, under a usb microscope, I tried to move every pin with a needle, they are all correctly soldered. Ive followed the lines from the micro usb and took the voltage at the first thing ive spotted, the 5volt I got on the motherboard was between the ground and a capacitor, wich are a bit far from the usb plug. Wich proves that the usb plug was not faulty. Anyway, ive manually recharged the battery using a tool to recharge lithium battery and put it back to the tablet. And now the tablet seems to work well and recharge the battery as it is supposed to be. Ive recharged it from 91% to 97% and looks to work fine. I think that if the battery are completely discharged, it wont recharge again, until I give it a little boost on the battery. So I will try to drain the battery tonight with a little game running in loop, and see tomorrow if it will wake up again. I will also try another battery on it, to see if it’s the battery or the tablet. Will keep you updated with this strange bug
