LG 42PX4R, Service Manual

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3. Protect Mode
(1) Symptom
Ø
After once shining, it does not discharge minutely
from module
Ø
The Rely falls(The sound is audible “click”)
Ø
It is converted with the color where the front LED
is red from green.
(2) Check following
Is the Power Board
normal ?
Replace Power
Board.
Is output the normality Low/High
voltage except Stand-by 5V?
Yes
No No
Is the each connector
normal?
Replace the
connector.
Replace
Y-Board.
After connecting well each connector,
the normality it operates?
Yes
No No
Is the Ctrl Board
normal?
Replace
X-Board.
Is the output voltage normal after
remove P1, 2, 4, 9, 10 connector of
Ctrl-B/D?
Yes
No Yes
Is the Y-Board
normal?
Is the output voltage
normal after remove
P5, P6 connector of
Y-B/D?
Is the Fuse(FS2) on Y-B/D normal?
(In case of open is replace)
Yes
No Yes Yes
Replace
Z-Board.
Is the Z-Board
normal?
Is the output voltage
normal after remove
P1 connector of Z-
B/D?
Is the Fuse (FS1, FS2) on Z-B/D
normal? (In case of open is replace)
Yes
No Yes
Is the X- Board
normal?
Is the output voltage normal after
remove P1, 2, 3, 4, 5 connector of
X-B/D?
After remove P1, P2, P3 output voltage
normality: Replace Right X-B/D
After remove P4, P5 output voltage
normality: Replace Left X-B/D
Yes
No Yes
Is the
VSC Board normal?
Is the output voltage normal after
remove P1001, P1100?
After crisis COF of each board, check the normality operates.
If in case normality operates, correspondence COF Fail is
replace the module.
After remove P1001, 1100 normal
operation: Replace VSC Board
Yes
No
Is the COF of X, Y, Z
normal ?
No
Yes
Yes