A2485 820-02100 Liquid Damaged 5V 0.03A

[it-solve]

Not turning on, a liquid around UF500, opposite side of U7700, underneath U5000
Corroded and knocked off R8170, replaced it.

PPVBAT_AON - 0V
PPDCIN_AON - 5,19V
PPBUS_AON - 12.9V
PP3V8_AON - 3.79V
PP5V_S2_MAIN - Jumping voltage at about 2.5V
PP1V2_AWAKE - Jumping too under 1V


I dont see any liquid around UC260. Its output is oscillating. Shall I replace or is there an easy way to cut off its output from the rest of the schematic and test if oscillating in case it is affected by the rest of the line?

 

[2informaticos]

Test removing RC260.

 

[it-solve]

I can confirm that P5VS2TPS_PWR_EN is also oscillating
P5VS2_PWR_EN too is oscillating
PP1V8_AON - 1.79V

 

[2informaticos]

"PP1V2_AWAKE - Jumping too under 1V"
Still jumping with RC260 removed?

 

[it-solve]

yes jumping at around 0.2-0.3V with removed RC260.
PP5V_S2_MAIn - 0V

 

[2informaticos]

Then the problem is before of 5V_S2 appearance.

Check all LDOs of U7700 and U8100.