Power On Trouble; Only For Training And Service Purposes - LG KP270 Service Manual

4.2 Power on trouble

32.769KHz clock at X101 32.769KHz clock at X101
26MHz clock at U502 is 26MHz clock at U502 is
PWRON pin(TP3) is high PWRON pin(TP3) is high
Before push the end key? Before push the end key?
PWRON pin(TP3) is low PWRON pin(TP3) is low
when push the end key? when push the end key?
LDOs output(C223,C207, LDOs output(C223,C207,
C209,C217,C218,C221,C232,C234, C209,C217,C218,C221,C232,C234,
C236,C237,C239) of U202 C236,C237,C239) of U202
Copyright © 2008 LG Electronics. Inc. All right reserved.

Only for training and service purposes

Start Start
Battery Voltage, higher Battery Voltage, higher
Than 3.2V? Than 3.2V?
YES
is ok? Click TP1 is ok? Click TP1
YES
ok? Click TP2 ok? Click TP2
YES
while push the end key while push the end key
is ok? is ok?
Power on is ok? Power on is ok?
END END
4. TROUBLE SHOOTING
NO Change or Charging Change or Charging
the Battery. the Battery.
NO
Check soldering Check soldering
or change X101 or change X101
NO
Check soldering or Check soldering or
Change U101, U504, U502,X501 Change U101, U504, U502,X501
NO
Resolder R202 Resolder R202
NO
Check soldering R220, Check soldering R220,
Q202 or change Q202 Q202 or change Q202
NO
Check soldering or change Check soldering or change
U202 and relevant component U202 and relevant component
NO
Change the main board Change the main board
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LGE Internal Use Only