820-00165 water damage no power no led

[lincev]

hi all, I have this board with liquid damage, it has been cleaned and does not appear to have serious damage.

I have changed U5110 but without success because I have short to ground in PP3V42_G3H

Some measures

PP3V42=0.17V
PPBUS_G3H=0.22V
PP3V3_S0=0v
PP3V3_S5=0

 

[2informaticos]

"I have short to ground in PP3V42_G3H"
What's the exact resistance?

U7090 gets correct VIN?

 

[lincev]

PP3V42_G3H with short value= 02.3 ohms (scale 200)

U7090 PPVIN_G3H_P3V42G3H=15.57v

thanks

 

[2informaticos]

You should find the culprit injecting voltage there.

 

[lincev]

I have injected voltage 2v with 0.04a nothing.. but up to 2,8v and the short to ground has disappeared, value to ground 160 change 340 change 160 10/15 second again short to ground.. value 019 mode diode and resistance now 21.4

 

[2informaticos]

May have a leaky capacitor, or accumulated crap underneath SMC.
Which area has been affected by liquid spill?

 

[lincev]

In these areas, near U7090, U3090 and U5000 on these sides, I have doubts about securing the components.

 

[2informaticos]

Change the filter caps near L7095.
Also reball SMC.

 

[lincev]

nice !! thanks only with reball SMC now I don't have short but I don't have led green or orange

new voltages

U5110
1 PP3V42_G3H=3.40v
3 PP3V42_G3H_SMC_SPVSR=3.40v
4 SMC_MANUAL_RST_L=2.71v
5 SMC_RESET_L=3.36v
6 SMC_LSOC_RST_L=3.38v
7 SMC_ONOFF_L=1.21v
8 PP3V3_S5_AVREF_SMC=3.26v

 

[2informaticos]

"7 SMC_ONOFF_L=1.21v"
Same with keyboard disconnected?
Check R5170.

 

[lincev]

For the repair I only have i/o board with flex data and fan connect

R5170 is bad, change now I have SMC_ONOFF_L=3.39v but any led with charger genuine

neither power or fan in smc bypass mode

 

[2informaticos]

Do you get 3V3_S5/SUS now?

 

[lincev]

yes but I have problem with 3v3_s5

R5590
1 PP3V3_S5=3.30v

U8130
1 PP3V3_S5=0.20v <---- why?
2 PP3V3_SUS=3.30v

 

[2informaticos]

Broken trace?

 

[lincev]

The track is fine, I already checked, sorry I was confused, there were two boards and it measures the opposite pin SUS_PGOOD_CT

thanks

 

[2informaticos]

Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L, at same time.

 

[lincev]

PM_PWRBTN_L=3.38v constant, no pulse drop

 

[2informaticos]

Did you use keyboard, or SMC_ONOFF_L pads?
Do you have 3.3V there?

 

[lincev]

pads of R5115

there? in SMC_ONOFF_L yes 3.3v

 

[2informaticos]

Try another SMC...