820 - 3437 - b , dead

[estelanim416]

Hi

No light on the connector no fan spin.
Tried with known good I/O board found signs of corrosion on c0895 and the test pads around it but after cleanup the lines seem to be ok still no power

PPVRTC_G3H - 3.39V
RTC_RESET_L - 3.39v
PCH_SRTCRST_L - 3.39v
PCH_INTRUDER_L - 3.39v
PCH_INTVRMEN - 3.39v
SMC_ADAPTER_EN - 0v
PM_BATLOW_L - 0v
SMC_PM_G2_EN - 0v
SMC_RESET_L - 3.38v

Please assist
Thank you in advance

 

[piernov]

PPBUS_G3H? Liquid near SMC or J6100?

 

[estelanim416]

PPBUS_G3H - starts at 0.5v then drains down it seems, it was fine yesterday so not sure if I done something to affect it

No liquid nor any visible corrosion near SMC or J6100

 

[2informaticos]

The mentioned signals and voltages are still present?
Do you use original Magsafe 2 charger?

Post U7100 basic voltages; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.
Also check diode mode to ground at L7130.

You should reball SMC...

 

[estelanim416]

Hi,
Yes, those signals and voltages are still present
yeah, that charger is a replacement so no, not original one

u7100
1 - 13.87v
2 - 0.31v
3 - 0v
9 - 0.03v
12 - 3.34v (its back!)
13 - 3.36v
14 - 0v
15 - 0.04v
17 - 0.5v slowly draining down
19 - 5.05v
20 - 5.05v
27 - 0.5v draining down to 0v

L7130 diode mode to ground - diode mode and continuity check are the same function on my multimeter - dont know how to interpret the results. With COM to ground on both pins it starts by signalling continuity, then number grows to 2k and then it just stops at 1 as in infinite resistance

I will look into smc reballing

 

[2informaticos]

"3 - 0v"
Fix ACIN problem first...