A1706 emc3163 touch bar not working after display replacement.

[2informaticos]

Who talked about caps???
"One of U7410/20/30 is shorted"
PLEASE, pay atention when you read the posts.

Do you mean these chips are still onboard?
Then remove U7420 first.

 

[manumathew.017]

Sorry, My approach was different. My Apologies.
Back to the board, I have removed U7420, Now PPBUS_G3H gives 0.373V in diode mode. Which means there is no short. Should I replace the FDMF5808A (U7420) with a new one?

 

[2informaticos]

New, or old from other board.
Just be sure no short present on PPBUS_G3H, after chip is soldered on the board.

 

[manumathew.017]

Hi,
I have replaced U7420, Now all the voltages are there except PPVCCSA_S0_CPU and PPVCC_S0_CPU. There is some common signal missing, I couldn't check the PWM pin. CPUCORE_FCCM is 0V and PVCC is 13V and PP5V_S0_VCORE is 5V.

 

[2informaticos]

Very likely dead CPU, because of overvoltage caused by U7420.

 

[manumathew.017]

Really?

 

[manumathew.017]

Is there anything I can do, Or I should scrap this board? Is there any option to confirm it is the CPU that is dead?
Maybe a stupid question, Will it be possible to replace the CPU by a professional micro soldering company?

 

[2informaticos]

"Very likely" unfortunatelly...