820-3435 liquid damaged


New member
Got this liquid damaged 820-3435, liquid around U6100 and u7600. CLeaned it up a bit looks pretty decent. Now it doesnt turn on but I have a pulse on L7520 and Enable on pin 4 of U7501, but missong 5V, 3.3 is present. Does that mean U6100 is working as I get the 5V signal and I have to look for another issue down the line?

Edit: im missing 3V3_SUS on U6100, missing PP3V3_S4, I have 3.3v on U8000 but no enable signal
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Staff member
BIOS is not involved in 5V generation.
In fact, as mentioned, U6100 is not even powered up.
If you have enable present on pin 4/U7501, then 5V power rail should come on.
Corresponding signal comes from PM_SLP_S4_L, or PM_SLP_S5_L; depending which resistor R8177/79 is soldered on the board.
If you really have that enable signal, at least PM_SLP_S5_L shoud be high.
In this case, S4_PWR_EN must be high too and U8000 should get enable signal.
If is the case, change U8000.


New member
Ok there was indeed a corroded trace near U6100, after fixing the line and give it a good cleaning, working again :)