820-00138 - Not Turning On

[iClub]

This mac came from another service with flux on u7501, Q8150, PCH Done reflow, and other components.


Voltage:

PPbus_g3h 12.6V; PP5V_S0 4.3V; pp3v3_s0 3.35V; PP3V3_S5 3.35V ;ALL_SYS_PWRGD 51mV, pulsing.

The fan rotates in SMC bypass mode.



diode mode;

L7630 0.088V
L7870 0.020V
L7330 0.019V
L7320 0,020V
L7310 0,174V
L7520 0,425V
L7195 0,335V
L3095 0,533V

Coil voltage;

L7630 0.485V
L7870 1.5V
L7330 0V, no pulse
L7320 0V, no pulse
L7310 0V, no pulse
L7560 3.35V
L7520 4.35V
L7195 5.5V
L3095 0V

 

[2informaticos]

5V_S4 looks too low; did you check it at C7552/4?
Check all components in that area, especially R7520/21/45 and C7524.
Be sure all solders and traces are good.

You have a problem with 1V05_S0 power supply.
Check all around U7600 and L/Q7630; pay atention to R/C7630.