tcampbell34
Member
Hello. I got an 820-00281 that is liquid damaged and has low PPBUS voltage. Every liquid damage indicator on the board is red, but only found corrosion around the backlight circuit and left speaker circuit. Board is using 20v 0.03v when I connect to just the charger. PPBUS starts at 0v when the charger is first connected and then after maybe 30 seconds or so, it starts at about 0.2v and slowly works its way up to around 0.77v and then stays like that steady. I took some measurements and figured it was a U7000 issue so I replaced it, but still have the same issue. Took another look over the board an noticed small amount or corrosion on pin 12 of Q7040. I replaced both Q7040 and Q7030, but still same issue. PPBUS is not shorted to ground either (0.383 @ F7000 in diode mode). Not sure where to look next.
PPBUS_G3H - 0.77
PP3V3_G3H - 3.4
TBA_GATE_Q1 - 0
TBA_GATE_Q2 - 0
TBA_GATE_Q3 - 0
TBA_GATE_Q4 - 0
PPVIN_G3H_P3V3G3H - 19.8
TBA_AUX_DET - 5.07
HPWR_EN_L - 3.36
SMC_RESET_L - 3.4
TBA_VDDA - 5.07
TBA_VDDP - 5.07
PM_EN_P3V3_G3H - 5.08
PPDCIN_G3H_CHGR - 19.8
SMC_BC_ACOK - 3.4
CHGR_AMON - 0
CHGR_BMON - 0
PPBUS_G3H - 0.77
PP3V3_G3H - 3.4
TBA_GATE_Q1 - 0
TBA_GATE_Q2 - 0
TBA_GATE_Q3 - 0
TBA_GATE_Q4 - 0
PPVIN_G3H_P3V3G3H - 19.8
TBA_AUX_DET - 5.07
HPWR_EN_L - 3.36
SMC_RESET_L - 3.4
TBA_VDDA - 5.07
TBA_VDDP - 5.07
PM_EN_P3V3_G3H - 5.08
PPDCIN_G3H_CHGR - 19.8
SMC_BC_ACOK - 3.4
CHGR_AMON - 0
CHGR_BMON - 0