820-00850 stuck on 5V 0,01A

[Dozer]

on all 4 ports the same
PPBUS_G3H 12.26V
PP3V3_G3H is missing

short to GND in PP3V3_G3H
via thermal camera and injection of 2V found damaged C7807
i pulled it from the board, the short is also away, in diode mode i get L7660 Pin 1 0.413 was 0,0

board back in the case with accu, no difference,

PP3V3_G3H is now 0.6V

checked U7650 all pins in diode mode almost like in the boardview (openboarddata)

checked all pins of all 4 ports, all ok



need some help what now ?

 

[Dozer]

foud burned R7900

like in repairwiki described "... If PP3V3_G3H had a short circuit, but the board stays at 5V and PP3V3_G3H is still missing, it can be due to R7900 (0 Ohm Resistor between PP3V3_G3H_RTC and U7800 PMIC, that takes PP3V3_G3H_RTC input and outputs it as PP3V3_G3H). Short cuircuit on PP3V3_G3H can burn out R7900 (may be visually intact). Check R7900 resistance. ..."

working now
problem solved