820-3332 no fan spin no chime, mouse lights up

[Repairable]

came in with water damage around u7000 repaired some traces and replaced u7000.
after that I took the board to Louis and it just turned on,,, around the right fan where its connected to the board the screw bracket is broken off.

today I had some time and picked up the board again,.

found a short on u5850 after replacing it short is gone.

now I also have pm_slp_s4_l back.

no fan spin and no vcore

CPUIMVP_TON both resistors measure good 181.9k and 182,1k
also when measuring from the pin 1 red and pin 48 black 364k

any idear where to go next.

 

[Repairable]

no cpuvcore

PP3V3_S0 present


u7950

pin 1 0.021v
pin 2 0.064v
pin 3 0
pin 4 0
pin 5 0
pin 6 0
pin 7 0
pin 8 3.3

missing CPUIMVP_PGOOD
missing ALL_SYS_PWRGD

CPUIMVP_PGOOD comes from u7400
pin 46 5v
29 5v
19 5v

CPUIMVP_VR_ON enables the u7400 chip


CPUIMVP_VR_ON comes from ALL_SYS_PWRGD

q7950
pin 1 0.002v PP1V05_S0_VMON
pin 2 un NC
pin 3 0.020v ground
pin 4 0.020v ALL_SYS_PWRGD
pin 5 1.068v VMON_3V3_DIV
pin 6 3.27v PP3V3_S5_VMON
pin 7 0 PP1V5_S3RS0_VMON
pin 8 2.7v NC

 

[aprendiz]

ALL_SYS_PWRGD, cames from the point where R7967 is tied to R7963-R7969, if one of the PGOOD signals is not coming high this will pull down ALL_SYS_PWRGD.... Measure big coils and check what voltage is missing.....

 

[Repairable]

ty aprendiz, so its indeed the other way around, first u7960 line up then q7950
ill check them thanks

 

[aprendiz]

U7960 is not present, so only resistors....

 

[Repairable]

Yup I mean that. With "line up" on schematic.

 

[Repairable]

oke wanted to measure today, I pluged in the board and had 0 on the first few resitors.
I then stoped and went back to the power lines.
when I came to PP3V3_S0 I got 0 at probing one of the caps.

when I released the probe the fan started to spin.

I then unplugged to see if I could reproduce. tobad no.

but now I don't have any volts at
PP3V3_S3 0.020v
PP3V3_S0 0.094v

I got 3.34 volts at PP3V3_S5

 

[dukefawks]

You are measuring S0 voltages while S3 is not even there. Is SLP_S4 high?

 

[Repairable]

yes I measured it again because it was present before. s5->s3>s0

PM_SLP_S4_L 3.31v

 

[Repairable]

PP3V3_S3 3.3v

PP3V3_S0 3.3v

 

[Repairable]

SMC_LID 3.4v

horrible,, second time the logic board is just booting and gives fan spin while measuring around, even thou totally different place. then disconnecd charger and no boot again..........

 

[dukefawks]

Corrosion somewhere. Impossible to remotely diagnose, inspect all areas that had corrosion. Maybe under SMC if there was corrosion there.