[SOLVED]820-3115 - Dead

[Alan.L]

came in liquid damaged, corrosion on clock area, SMC area, fan area and ISL area.

it didnt get a green light initially, so i've replaced the ISL, SMC. now i get green light.

i also have repaired the clock area, replaced u2600 and some other stuff there.

replaced u7200, as there was some corrosion there.

U6990's (PPVIN_G3H_P3V42G3H) Pin 7 - trace was destroy, i replaced U6990 and fixed the trace.

SPI ROM is missing PP3V3.



PPBUS_G3H = 12.59
PPBUS_S5_HS_COMPUTING_ISNS S = = 12.59
PPBUS_S5_HS_OTHER_ISNS = 12.59
PP5V_S5_LDO = 4.94
PP3V42_G3H = 3.48V
PPVRTC_G3H = 3.3
PP5V_SUS = 0
P5VSUS_SS = 4.8V
PP5V_S3 = 0
PP5V_S0 = 0
PP3V3_S5 = 3.3
PP3V3_SUS = 0
PP1V8_S0 = 0
PP1V5_S3_DDR = 0
PP1V5_S0 = 0

​​​​​​​
C1802/03
—————————————
PCH_SRTCRST_L = 3.317
RTC_RESET_L = 3.317

 

[2informaticos]

"PP5V_SUS = 0
PP3V3_SUS = 0"
Do you have PM_SLP_SUS_L high level?
Check voltages at Q7820/22/40..

 

[aprendiz]

Check U7940, voltage on each pin?

 

[Alan.L]

PM_SLP_SUS_L = 3.33

Q7820
--------
PP3V3_S5 = 0V
P3V3SUS_EN_L = 3.29
P3V3SUS_SS = 3.29
PP3V3_SUS_FET = 0V


U7940
------------
pin1 = 0
pin3,4 = 0.6v
pin5 = 3.3v
pin6 = 3.3v


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mmmmm damn,,

i've accidentally got it working..i get fan spin and chime.

if i press down with my finger on this area, the board will work:

there must be a bad trace or damaged component somewhere but the stuff there and back of the board looks good.

 

[Alan.L]

actually i just need to touch it with my finger and will work. is it possible my skin's resistance causing it to work?



edit: i found it. if i put a micro brush with iPA on between DCIN_VSENSE_EN" and "DCINVSENS_EN_L" test points the board will start.

i've replaced Q5490, r5492, r5494, and didn't solve.

 

[dukefawks]

SMC_BATLOW problem. Check R5040, Q5040. Possible SMC problem too.

 

[Alan.L]

thanks for your tips. it was U7940, problem solved.