A1466, 820-00165 PP3V3_S5 short on the GND

k_konstantin

New member
Hello everyone, in general


There was a slight flooding in the area of U1900 + corrosion. There was no backlight, but the beech started and showed a picture. Locally cleaned the board in the area of U1900, removed and installed U1900, soldered the nearby resistors and capacitors, after that there is no more startup and a short circuit appeared on PP3V3_S5, PP3V3_S0, PPVRTC_G3H

What was done:
Removed U1900, C1910, U7701, U6100, U6101, C6101, C3280, C3281, C8070 There is no result

L7430 is removed
Pin 1 (PP3V3_S5_REG_L) is clean
Pin 2 (PP3V3_S5_REG_R) is shorted on the GND

Diod mode:

PP3V3_S5 .004
PP3V3_SUS .004
PPVRTC_G3H .002
PP3V3_S0 .005

No idea
 

2informaticos

Administrator
Staff member
Having short on all these rails is really bad; it points to dead PCH.

Did you remove power when checked diode mode?
Remove all filter caps from PPVRTC_G3H and check if still short there.
 

k_konstantin

New member
Having short on all these rails is really bad; it points to dead PCH.

Did you remove power when checked diode mode?
Remove all filter caps from PPVRTC_G3H and check if still short there.

-Did you remove power when checked diode mode?
what do You mean? Have I disconnected the battery and MagSafe?

-Remove all filter caps from PPVRTC_G3H and check if still short there.
You mean C0890, C0891 and C0892?
 

2informaticos

Administrator
Staff member
"what do You mean? Have I disconnected the battery and MagSafe?"
Yes, cannot check diode mode with power applied on the board.

"PPVRTC_G3H still short on the GND"
If you removed mentioned caps from RTC power rail and also U1900, then PCH is shorted to ground.

BTW, any reason to quote an entire post visible few centimeters above?
Write directly on reply box, instead of clicking Reply button.
Please, maintain forum aesthetic...
 
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