Protect Mode - LG MU-42PM11 Service Manual

3. Protect Mode

(1) Symptom
Will not fully turn on
¯
The Relay "clicks"
¯
Front LED changes from Green to Red
¯
(2) Check follow
Is the Power Board
good?
Yes
Are all connectors
connected?
Yes
Is the Y-Board good?
Yes
Is the Z-Board good?
Yes
Is the X-Board good?
Yes
Is the Ctrl Board
good?
Yes
Is the VSC Board
good?
Yes
Is normal the
COF of X, Y, Z?
TROUBLE SHOOTING GUIDE
No
Is output the normality Low/High
voltage except Stand-by 5V?
No
After connecting each connector well,
is operation good?
No
Check Fuse(F52) on Y-B/D?
(In case of open, replace fuse)
No
Check Fuse(FS1, FS2) on Z-B/D?
(In case of open, replace fuse)
Is the output voltage good after
No
removing P1, 2, 3, 4, 6, 7 connector
of X-B/D?
Is the output voltage good after
No
removing P1, 2, 101, 300, 701, 702
connector of Ctrl-B/D?
No
Is the output voltage good after
removing P1000, P1200?
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
No
Is the output voltage
Yes
good after removing
P5, P6 connector of
Is the output voltage
Yes
good after removing
P1 connector of Z-
If after removing P1, P2, P3, P4 the output
Yes
voltage is normal: Replace Right X-B/D.
If after removing P6, P7 the output voltage
is normal: Replace Left X-B/D.
Yes
If after removing P1000 the output is
Yes
normal: Replace Analog Board
If after removing P1200 the output is
normal: Replace Digital Board
- 17 -
Board.
Replace
connector.
Yes
Y-B/D?
Yes
B/D?
Replace
X-Board.
Replace
Y-Board.
Replace
Z-Board.