820-4924 2015 Retina 13in green light on charger no power on need some help

[supamodz]

Hi guys, I'm working on a 820-4924 board green light on charger, unit will not power on no obvious shorts to ground i cant get it to turn on any ideas here are my readings im confused about ppbus_s4 rail is that normal?

PPBUS_G3H 12.58V
PPBUS_S5_HS_COMPUTING 12.58
PPBUS_S5_HS_OTHER5V 12.58
PPBUS_S5_HS_OTHER3V3 12.58
PPBUS_S4_X239 0.00
PPVIN_S4_TPAD 0.00
PPDCIN_G3H_ISOL 15.17
PPDCIN_G3H 14.59
PP3V42_G3H 3.41
PPVRTC_G3H 3.34


PP5V_S5 5.024
PP3V3_S5 3.348
PP3V3_SUS 3.347
PP1V05_SUS 1.060

 

[dukefawks]

Check S3 busses for pulsing/power cycling, preferably use a scope because the pulses are only a few milliseconds. Also history?

 

[supamodz]

Check S3 busses for pulsing/power cycling, preferably use a scope because the pulses are only a few milliseconds. Also history?

pp5v_s3 reg shows no voltage on the meter on the scope i get 3.4v on pin 2 of u7501 without grounding the circuit when i ground it i get 0v im confused customer stated just stopped working

 

[dukefawks]

PPDCIN shows 14.6V? Are you using a 45W charger? It MUST be 60W or higher.