LG MX8550 Service Manual page 127

MX8550
of CON 201 of key PCB . Is there any pulse when you keep
LG Electronics Inc.
Checking Flow #2
Checking Flow #2
2
Check the voltage at pin 52,
53 of CON201 of key PCB . Is there any pulse when you
keep moving the wheel ?
NO
Check the voltage at pin 52,
53 of CON 102 of FPCB . Is there any pulse when you keep
moving the wheel ?
NO
Check the voltage at pin 57,
58 of CON 101 of FPCB . Is there any pulse when you keep
moving the wheel ?
NO
Check the voltage at pin 57,
58 of CON 600 of Main B /D. Is there any pulse when you
keep moving the wheel ?
NO
Replace Main B /D
1
Check the voltage at pin 20,
moving the wheel ?
NO
Check the voltage at pin 20
of CON 102 of FPCB . Is there any pulse when you keep
moving the wheel ?
NO
Check the voltage at pin 35
of CON 101 of FPCB . Is there any pulse when you keep
moving the wheel ?
NO
Check the voltage at pin 35
of CON 600 of Main B /D. Is there any pulse when you
keep moving the wheel ?
NO
Replace Main B /D
Replace the wheel
YES
Resolder CON 201 of key
PCB
YES
Replace FPCB
YES
Resolder CON 101 of FPCB
YES
Replace key PCB
YES
Resolder CON 201 of key
PCB
YES
Replace FPCB
YES
Resolder CON 101 of FPCB
YES
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