Macbook Pro A1398 - 820-3332A. Fan spins continuously on battery but no chime and no display. No fan spin without battery, Yellow light on Magsafe Adapter. Checked all voltage rails and results as below.
PPBUS_G3H = 12.6v
PPVIN_S5_HS_COMPUTING_ISNS = 12.6v
PPVIN_S5_HS_GPU_ISNS = 12.6v
PPVIN_S5_HS_OTHER_ISNS = 12.6v
PP18V5_DCIN_CONN = 16.3v
PP3V42_G3H = 3.4v
PP5V_S5 = 5.1 v
PP3V3_S4 = Missing.
What next?
PPBUS_G3H = 12.6v
PPVIN_S5_HS_COMPUTING_ISNS = 12.6v
PPVIN_S5_HS_GPU_ISNS = 12.6v
PPVIN_S5_HS_OTHER_ISNS = 12.6v
PP18V5_DCIN_CONN = 16.3v
PP3V42_G3H = 3.4v
PP5V_S5 = 5.1 v
PP3V3_S4 = Missing.
What next?