Baseband Trouble Shooting; Introduction; Device Cannot Power On; Measure Each Power-On Sequence Voltage Level - Asus P552W Manual

2.Baseband Trouble Shooting

2.1 Introduction

The purpose of this repair manual is to provide a general trouble
shooting guide for the defective
ASUS PDA phone GM2.
The repair methodology provided in this manual is strictly for the
GM2 model ONLY, trouble shooting
methodology for the other ASUS designed PDA phone will not be
included in this document.

2.2 Device Cannot Power On

The most common reasons that will cause device to fail to power
on is due to defect components or incorrect power-on sequence. It is
recommended to observe and examine if there is any obvious external
damage on the PCB or any on board component first. If not, please
hook the power supply and check if there is any current, If there is no
current observed on power supply, please push the power button to
power on the
system first and follow the following debugging process: V_BAT =
power supply voltage

2.2.1 Measure each power-on sequence voltage level

A. V_BAT = power supply voltage ,check C1103.1
This is to make sure that the power source is at the correct level. If
the measured voltage level is lower than the supplied main voltage, it
is likely that there is a current leakage on the V_BAT power domain.
(Generally this will cause high current consumption on the power
supply). If this is observed, please check all the components that are
connected to the V_BAT net, and examine if there is any possible
defect. If the measured voltage is equal to 0V, and it is not shorted to
GND, please check if there is any defect on the battery connector.
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GTC ■ Service Manual
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