2D72 charges very slowly

ttt · Post time 2019-1-6 09:21:36

Edited by ttt at 2019-1-6 09:23

My 2D72 charges very slowly. It took entire day to go from fully drained battery (was shipped this way) to 2 bars.

It only consumes 90 mA from USB when powered off, but charging, which is obviously too low.

Is this just my device, or is this all of tehm?

ttt · Post time 2019-1-6 15:32:42

Well, that sucks.

After some playing around with batteries, I've got a dead unit. Some quick troubleshooting lead to dead H&M Semi HM4052. It is a battery charger/switch power supply that is used to supply the rest of the system.

Interestingly, this IC was clearly reworked on my device, there are signs of flux all over the place (which may have been the source of poor charging).

The IC seems to be unobtainable.

So now I can transform this unit to USB-only by bypassing this IC and dropping the input voltage to 3.8 V (normal output of HM4052). Or diode-switch USB and battery voltages and skip battery charging.

Both options kind of suck.

I need to sleep on it. If anyone knows the source for HM4052, I'd be glad to hear.