Power On Troubleshooting - LG -P970 Service Manual

4.9 Power ON troubleshooting

The main power source of LGP970 is provided by 2 chips which are TWL5034 and XMM6160 (Communication
processor). Since XMM6160 only powers up normally when OMAP3630 is properly powered therefore, TWL5034
are the actual ones to take look at.
Power ON sequence of LGP970 is,
PWR key press → PM_ON_SW_N go to low (R409(TP1), TWL5034 POWER_ON_SW_ pin(A11)) →TWL5034 Power Up →
PWR key press PM_ON_SW_N go to low (R409, TWL5034 POWER_ON_SW_ pin(A11))
REGEN → 1.8V_MMC_EN(C456_TP) → 1.8V_VIO(L404_TP3), 1.8V_CSI(C454_TP4), 3.0V_MOTION (C45_TP5), 1.8V_
REGEN 1.8V_MMC_EN(C456)
AUDIOAMP(C460_TP6) → VDD1_CORE(L40_TP7) → VDD_CORE(L403_TP8) → 1.8V_VPLL1(C459_TP9) → OMAP_PWR_
1.8V_AUDIOAMP(C460)
RESET goes high!
goes high!
LGE Internal Use Only
1.8V_VIO(L404), 1.8V_CSI2(C454), 3.0V_MOTION (C452),
VDD1_CORE(L402) VDD2_CORE(L403) 1.8V_VPLL1(C459)
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4. TROUBLE SHOOTING
TWL5034 Power Up
OMAP_PWR_RESET
Only for training and service purposes