820-2915 won't run on charger only, runs on battery


pin 1 - 0V
2- 16.5V
3 - 3.95V
12 - 3.48V
13- 3.48V
14- 0V
15- 0V
17- 0.625V
19 - .5V dropping
20- .5V dropping
diode drop on pin 19/20 is .457
27 - 0.41V
resistance 17/18 = 2.6 ohms, 27/28 =20.4 ohms
PPBUS_G3H - dropping toward zero 0.98V
PPBUS diode to ground = .431V

Changed u7000 twice with same readings


Not sure! Maybe it was there before and I didn’t have my lead up on pin 1 well. I only changed the one chip and nothing else. Didn’t poke around much while connected to power to have shorted anything.

On other charger circuits I’ve seen ~16V before on pin 1 occasionally does that usually imply bad isl? also Does the isl produce the voltage at 19,20 and 27? Obviously I struggle to understand schematics. I have difficulty at time identifying what are inputs vs outputs unless it specifically says right on the pin of chip in schematic