820-03597 5V 0A

[ajdoc]

No liquid damage.
UF400 was getting warm as PP3V3_UPC0_LDO was shorted.

Replaced UF400 from a donor board (same location).
Short is gone but stuck at 5V. Goes to 0.24A and after a few seconds drop to 0A and stays at 0A.

Because UF260 is also on PP3V3_UPC0_LDO firstly I re-flashed UF260 with the same .BIN file but no luck.
Then I swapped UF260 from the same donor board and still no luck so soldered original UF260 back.

With charged battery MacBook turns on - no issues. Just wont charge.

Readings - diode mode | voltage
UF400
PP3V3_S2_LDO - 0.444 | 3.3V
PP1V5_UPC0_LDO_CORE - 0.490 | 1.54V
PP3V3_UPC0_LDO - 0.471 | 3.23V
PP1V8_UPC0_LDO - 0.514 | 0V (on known good board I have 0V as well)

UF500
PP3V3_S2_LDO - 0.444 | 3.28V when 0.24A from charger and when 0A on charger then 0V (on UF400 even when at 0A I have 3.3V)
PP1V5_UPC1_LDO_CORE - 0.495 | 1.53V
PP3V3_UPC1_LDO - 0.480 | 3.21V
PP1V8_UPC1_LDO - 0.538 | 0V (on known good board I have 0V as well)

U5500 LDOs in diode are are correct as well.


I have another board which is fully working to compare reading.

 

[ajdoc]

Because PP3V3_S2_LDO on UF500 was dropping to 0V i replaced UF500 (same IC location on donor board).
Now PP3V3_S2_LDO on UF500 is pulsing 0V > 3V > 0V

From charger 5V 0.06A > 0.4A > 0A > 0.06A etc

I noticed under thermal camera whole row RC622-27 is getting warm.
PP5V_S2 is not shorted.
Diode mode on CC334 0.165 (good board 0.280)

I was suspecting QC620 but still the same with new QC620
On RC620 P5VS2_PWN_EN is pulsing (good board stable 1.79V)
Removed QC620 and P5VS2_PWW_EN is still pulsing.

PPBUS_AON is 12.26V and there is a short drop every a coupe of seconds.

I am lost now.