Power On Troubleshooting - LG GT540 Service Manual

4.9 Power ON Troubleshooting

Power On sequence of GT540 is :
Power key press KPD_PWR_N(VA20) go to low
VREG_MSMC2_1.2V(C107), VREG_MSME_1.8V(C161), VREG_MSMP_2.7V(C106), VREG_MSMA_2.6V(C109),
VREG_TCXO_2.85V(C218) power ON
Battery voltage higher than
TP1 hight to low when key pness?
TP2(1.2V), TP3(1.2V), TP4(1.8V),
TP5(2.6V), TP6(2.6V), TP7(2.85V)
power up currently?
Redownload SW image
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Only for training and service purposes
Phone booting and PS_HOLD(D18) go to High
START
3.70V(OCV)?
Yes
Yes
Yes
is clock OK?
TP8:19.2M
TP9: 32.768Khz
Yes
PM7540 Power Up VREG_MSMC1_1.2V(C104),
No
Change or charging the Battery
No
Check correctly working powerkey
No
Change the Main board
No
Change the Main board
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4. Trouble Shooting
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