Troubleshooting
4-2
4-2. Action by symptom
4-2-1. When the LCD screen does not come out
No
No
No
Check the connection between
Check the connection between
F3 F4 cable and terminal block.
F3 F4 cable and terminal block.
Check indoor power.
Check indoor power.
Replacement of Assy PCB
Replacement of Assy PCB
(DB92-04639B (JN)/C(KN)/E(UN)/
(DB92-04639B (JN)/C(KN)/E(UN)/
G(RN)/F(CN)) due to 21V Backlight IC
G(RN)/F(CN)) due to 21V Backlight IC
problem.
problem.
Yes
Yes
Yes
Yes
Yes
Is the connection to the
Is the connection to the
F3F4 terminal block OK?
F3F4 terminal block OK?
Is the voltage across the
Is the voltage across the
F3F4 terminal 9 ~ 12V?
F3F4 terminal 9 ~ 12V?
C108 Is the voltage
C108 Is the voltage
between 18 ~ 24V?
between 18 ~ 24V?
Does it work normally
Does it work normally
after replacing?
after replacing?
ASSY DISPLAY (LCD) Replacement
ASSY DISPLAY (LCD) Replacement
(DB93-16995A)
(DB93-16995A)
C115 Is the voltage between
C115 Is the voltage between
both ends 5V?
both ends 5V?
Is the LCD connector
Is the LCD connector
connected properly?
connected properly?
No
No
Replace Assy PCB due to 5V DC DC
Replace Assy PCB due to 5V DC DC
Converter problem.
Converter problem.
LCD connector reconnect.
LCD connector reconnect.
(LCD cable white line / PCB black
(LCD cable white line / PCB black
line match)
line match)
No
Replacing Assy PCB.
Replacing Assy PCB.
(DB92-04639B
(DB92-04639B
(JN)/C(KN)/E(UN)/G(RN)/F(CN))
(JN)/C(KN)/E(UN)/G(RN)/F(CN))
Start
Start
End
21V
5V
GND
GND