820-00165 Short on U7400

[No-Clean]

U7400 was heating up when injecting voltage on PP5V_S5 replaced U7400, short on PP5V_S5 now gone and diode reading on PP5V_S5 is now correct, however no boot or USB activity, I tried 2 U7400 just in case before finding out the voltages below.

U7400 pin 17 is 0V
U1970 pin 2 is 0V

I think that is my problem, but in this case maybe CPU is dead, please help.

 

[2informaticos]

Do you get voltage at pins 12, 16, 6?

 

[No-Clean]

Sorry, I should have included that, yes all those 3 have the correct voltage, 5V, 3.3V and 1.8V

 

[2informaticos]

Then you should have voltage at L7430.
Post diode mode there.

 

[No-Clean]

Diode reading on L7430 is 0.245

 

[2informaticos]

Replace again U7400 and check all surrounding resistors.
Be sure to get good solders.
Also change Q7430 and R/C7425.

 

[No-Clean]

New U7400, Q7430 C7425 and R7425 and same exact behavior.

 

[2informaticos]

Possibly broken trace, or bad solders.