LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
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4.8 Power on trouble
Power on sequence of KC910 is :
PWR key press
→
PM_ON_SW_N go to low (VA700, PM6658 KPD_PWR_N pin#L4)
→
PM6658
Power Up
→
VREG_MSMC_1.2V(C506), VREG_S2_2.1V(C509), VREG_MSME_1.8V (R512),
VREG_S3_2.7V(C511), VREG_MSMP_2.7V(R513), VREG_MSMA_2.6V(R11),
VREG_TCXO_2.85V(C517) power up
→
PON_RESET_N assert to MSM
→
Phone booting &
PS_HOLD(D501) assert High to PMIC(PM6658)
Start
Battery volt. higher
than 3 .2V?
Press PW R key
Key pad L ED on?
VA700 h igh to low
when key press?
VREG_MSMC_1.2V, VREG_S2_2.1V,
VREG_MSME_1.8V, VREG_S3_2.7V,
VREG_MSMP_2.7V, VREG_MSMA_2.6V
VREG_TCXO_2.85V, power up?
Is c lock ok ?
X1000 : 19.2M
X500 : 32.768Khz
Change the Main board
Change or charging the
Battery
Follow the LED trouble
shoot
Check open Pattern
of power button
Check Dome Sheet
Change the Main board
Check the TXCO and SLEEP CRYSTAL
NO
YES
YES
YES
YES
YES
NO
NO
NO
NO