LG 42PC3R Service Manual page 20

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