820-4924 No 5v_s3 no power

[Ryanlen2]

Liquid damage on J4915 and has been removed for now. Also C7778 was damaged and replaced. No other visible damage.
Green light on charger.

PPBUS - 12.56v
PP3V42 - 3.429v
PPVRTC - 3.3v
PP5v_s5 - 5v
pp3v3_s5 - 3.3v
PP5v_s3 - missing
PPBUS_S4_X239 - missing (should I have this?)
PPVIN_S5_HS - 12.56v
PM_SLP_S4_L - Missing

SMC_Adapter_EN - 3.396v
L7560 - 3.342v

Thanks

 

[dukefawks]

Is there power cycling on 5V_S4? The usual suspects apply, U1900/50, U6100 termination resistors/traces. Check all rails for shorts.

 

[Ryanlen2]

Hey Duke.

Nothing on 5V_S4.

S5 going into U8060, .011V on 5V_S4_EN

Will check other things next.

Thanks.


Update-
Areas recommended check over and clean. Board is very clean. All TP's are still gold. No visible burnt traces or damage except for what I already specified.
Will check for shorts. When you say check all rails, do you mean main power rails and sub rails? (Everything on pg 68) Or just main power rails? Diode or resistance mode?

Thanks.

 

[dukefawks]

Just any rails, but most of interest would be CPU stuff.

Also you say green light on charger, but it must be orange!

 

[Ryanlen2]

Its orange yes. Sry.

 

[dukefawks]

The short check then?

 

[Ryanlen2]

Home now with 3 screaming kids on their vacation. Get to it in AM. Just wanted to know where to be checking.
thanks for the help.
Have a good night/day.

 

[Ryanlen2]

The only part that was damaged physically on the board was J4915. That leads to5v_s0, could that be fucking up S3?

?

This board is so clean I dont even know where to start. No shorts, checked all 1.5V/1.2V/1.8V/1.05V RAILS.