LG 42PC3RA-ZJ (CHASSIS:PP61A) Service Manual ▷ View online
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4. Protect Mode
(1) Symptom
1) After once shining, it does not discharge minutely
from module.
2) The Rely falls down.(The sound is audible “click”)
3) The front LED turn Green to Red.
3) The front LED turn Green to Red.
(2) Check following
Is normal PSU?
Exchange the
PSU
Does the Low/High voltage
operate normally?
Yes
No
No
Is normal cables?
Exchange the
cable
Exchange Y-
board
Do cable connect well each
wafer?
Yes
No
No
Is normal Ctrl B/D?
Exchange Ctrl board
Disconnecting cable(P4, 5, 6, 7, 10, 11)
at Ctrl board, are Va/Vs normal?
Yes
No
Yes
Is normal Y-board?
Disconnecting
cable(P1, P152)
at Y-board, are
Va/Vs normal?
Are Fuses(FS2, FS3) normal?
(Exchange the fuse at abnormal)
Yes
No
Yes
Yes
Exchange Z-
board
Is normal Z-board?
Disconnecting
cable(P1, P2, P6)
at Z-board, are
Va/Vs normal?
Va/Vs normal?
Are Fuses(FS1, FS2) Normal?
(Exchange the fuse at abnormal)
Disconnecting cable( P1,3,4,105)
at X-board, are Va/Vs normal?
Yes
No
Yes
Is normal X-board?
Disconnecting P1/P3, Va/Vs is normal :
Exchange Right X-B/D
Disconnecting P4/P105, Va/Vs is normal :
Exchange Left X-B/D
Yes
No
Yes
Is normal Main B/D?
Disconnecting cable(P301, P900, P1001)
at main B/D, are Voltages normal?
After crisis COF of each board, check the normality operates. If in case normality
operates, correspondence COF Fail is replace the module.
operates, correspondence COF Fail is replace the module.
Exchange Main board
Yes
No
Are COFs normal?
No
Yes
Yes
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5. No Raster
(1) Symptom
1) Front LED is Green.
2) The Set doesn’t discharge a little.
2) The Set doesn’t discharge a little.
(2) Check following
Is normal PSU?
Exchange the
PSU
Does the Low/High voltage
operate normally?
Yes
No
No
Is normal cables?
Exchange the
cable
Exchange Y-
board
Do cable connect well each
wafer?
Yes
No
No
Is normal Ctrl B/D?
Exchange Ctrl board
Disconnecting cable(P4, 5, 6, 7, 10, 11)
at Ctrl board, are Va/Vs normal?
Yes
No
Yes
Is normal Y-board?
Disconnecting
cable(P1, P152)
at Y-board, are
Va/Vs normal?
Are Fuses(FS2, FS3) normal?
(Exchange the fuse at abnormal)
Yes
No
Yes
Yes
Exchange Z-
board
Is normal Z-board?
Disconnecting
cable(P1, P2, P6)
at Z-board, are
Va/Vs normal?
Va/Vs normal?
Are Fuses(FS1, FS2) Normal?
(Exchange the fuse at abnormal)
Disconnecting cable( P1,3,4,105)
at X-board, are Va/Vs normal?
Yes
No
Yes
Is normal X-board?
Disconnecting P1/P3, Va/Vs is normal :
Exchange Right X-B/D
Disconnecting P4/P105, Va/Vs is normal :
Exchange Left X-B/D
Yes
No
Yes
Is normal Main B/D?
Disconnecting cable(P301, P900, P1001)
at main B/D, are Voltages normal?
After crisis COF of each board, check the normality operates. If in case normality
operates, correspondence COF Fail is replace the module.
operates, correspondence COF Fail is replace the module.
Exchange Main board
Yes
No
Are COFs normal?
No
Yes
Yes
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6. No Sound
(1) Symptom
1) Front LED is Green.
2) The Set display a screen, but a sound doesn’t output.
2) The Set display a screen, but a sound doesn’t output.
(2) Check following
Are Speaker Cables Good?
Are Speaker Cables Good?
Are Speaker units good?
Download EDID data
once more.
Exchange IC401
No
No
Yes
Yes
Are Speaker Cables Good?
Are Speaker Cables Good?
Are Speaker units good?
Yes
Yes
Is sound at Scart1/2
(or Component2)RGB,
or Side AV Good?
Are good some elements
(C, R, L, or Diode)
at Sound path?
Is IC800 good?
(Switching IC)
Is IC601 good?
(VCT-P)
1) Speaker part
2) Main board part
No
No
No
No
Yes
Yes
Yes
Is sound at HDMI Good?
Is EDID download
good?
Is IC401 good?
(AD9381)
No
Yes
If it dead or short,
exchange this elements
Exchange IC800
No
No
Exchange IC601
No
Is IC801 good?
(Amplifier)
Exchange IC801
No
If it dead or short,
exchange this elements
No
Is sound at RF, AV, or
Component1 Good?
Are good some elements
(C, R, L, or Diode)
at Sound path?
No
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7. Display the screen abnormally
(1) Symptom
1) Disp
lay the screen abnormally at specific mode.
(2) Check following
1) Noise appears at RF mode.
Is the Tuner part good?
Is the Tuner cable
connected well?
Are input voltage, I2C, and
CVBS output good?
Insert the cable exactly
Exchange the Tuner
Yes
No
No
No
Is Gaskets added well?
Is added the ferrite core
at cable?
Add the ferrite core
Add the Gasket
Re-assemble the SET
No
No
No
Yes
No
Is arranged the cable
well?
Re-arrange the cable
(Don’t cross the cable above a X or Z board)
No
2) Noise appears at Side AV.
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