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4. TROUBLE SHOOTING
4. BB Trouble Shooting
4.8 Power ON Troubleshooting
Power On sequence of U830 is :
PWR key press(Key PCB) → PM_ON_SW_N go to low(VA400),PM6650 KPDPWR_N pin(24) →
PM6650 Power Up → VREG_MSMC_1.375V(C627), VREG_MSME_1.8V(C628),
VREG_MSMP_2.7V(C618), VREG_MSMA_2.6V(C616), VREG_TCXO_2.85V(C603) power up
and system reset assert to MSM → Phone booting and PS_HOLD(R603) assert to PMIC
VREG_MSMC_1.375V,VREG_MSMP_2.7V,
VREG_MSME_1.8V,
VREG_MSMA_2.6V power up?
Start
Battery voltg. higher
than 3.28V?
YES
Press PWR key
Keypad LED on?
YES
VA400 high to low
when PWR key press?
YES
REG_TCXO_2.85V,
YES
Is clock ok?
X500(pin 3) : 19.2Mhz
X600(pin1,2) : 32.768Khz
YES
Change the Main board
- 100 -
NO
Change or charging the
Battery
NO
Check the Main PCB
NO
Check the Main PCB
NO
Change the Main board
NO
Check the TCXO
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Table of Contents
Troubleshooting
