(347) 552-2258 [email protected]

820-4924-A PPSUB_G3H shorted ground

M

macfix

Member
Hello everybody

I m working on liquid damaged 820-4924 board. Some one cleaned board, cant see burned items or corrosion. PPBUS_G3H is shorted ground when i inject voltage ppbus_g3h line after remove F7140 no where worming up:( checked every place board for any hot parts nothing.

Note: Checked usb ,thunderbolt and all connectors on board for damaged pins or like that.

What can i do next step?
 
A

aprendiz

Moderator
Measure on diode mode from pin 2 from F7140 to all big coils, no one should give you a low value or beep.....
 
D

dukefawks

Administrator
Yes there will be low resistance to the CPU Vcore coils. Measure F7140 to L7320, probably shorted and if so it will have taken out the CPU most likely.
 
M

macfix

Member
Thanks Duke after replace Q7310 and Q7311 shortcut was gone. But now when plug magsafe machine not power on. only usb mouse led flash one second and dead. Magsafe led is first green after orange

PPBUS_G3H - 12.5V
PP3V42V_G3H - 3.3V
PPVRTC_G3_PCH - 3.3V
PP5V_S5 - 5V
PP3V_S5 - 3V
 
You must log in or register to reply here.
Top