
- 13 -
TROUBLESHOOTING GUIDE
1. NO POWER
CHECK U4.
CHECK
U4 PIN 8 VOLTAGE
(5V) ?
NO
NO POWER
(POWER INDICATOR OFF)
CHECK ADAPTER,
AND FIND OUT
A SHORT POINT
AS OPENING
EACH POWER LINE
CHECK J1’S
VOLTAGE
(12V) ?
NO
CHECK L11
(OPEN CHECK)
CHECK
U5 Voltage
(5V) ?
NO
U13’S PIN11
0V ?
CHECK U13, AND
CHECK 5VA LINE
CHECK IIC LINE
CONNECTION
(U4, U1)
CHECK U3’S VCC,
XTAL, RESET
IS U3 PIN12
VOLTAGE REPEATED
AS PULSE SHAPE ?
NO
YES
YES
YES
NO
YES
NO PROBLEM
NO
CHECK KEY CONTROL
CONNECTOR ROUTINE

- 14 -
2. NO RASTER (OSD IS NOT DISPLAYED) – INVERTER
CHECK MICOM INV
ON/OFF PORT.
J4 PIN5
5V?
NO
NO RASTER
(OSD IS NOT DISPLAYED)
CHECK ADAPTER
J4 PIN10
12V?
NO
1. CONFIRM BRIGHTNESS
OSD CONTRL STATE.
2. CHECK MICOM DIM-ADJ
PORT
J4 PIN1
5V?
NO
REPLACE
INVERTER ASS’Y
CHECK
PULSE AS
CONTACTING SCOPE
PROBE TO CAUTION LABEL.
(CONTACT PROBE TO
CAUTION LABEL.
CAN YOU SEE PULSE
AT YOUR
SCOPE?
NO
REPLACE CCFL LAMP
IN THE LCD MODULE
YES
YES
YES
YES

- 15 -
1. CHECK PIN141, 142
SOLDERING CONDITION
2. CHECK X2
3. TROUBLE IN U3
U3
POWER PINS
3.3V?
NO
CHECK U2, U24
U3 PIN141, 142
OSCILLATE AS 14.3M?
NO
CHECK U5’S SOLDERING
CONDITION AND
CHECK CONNECTION LINE
FROM U3 TO J5
NO
TROUBLE IN CABLE
OR LCD MODULE
CHECK U12, U30
J5 PIN1
3.3V?
NO
YES
YES
YES
YES
3. NO RASTER (OSD IS NOT DISPLAYED) – gmzanl
NO RASTER
(OSD IS NOT DISPLAYED)
J5
PIN2 IS 65MHz CLOCK?
PIN4 IS 48KHz H-SYNC?
PIN5 IS 60Hz V-SYNC?
PIN37 IS 48KHz H-SYNC?
IS PULSE APPEARED
AT SIGNAL PINS?

- 16 -
CHECK U2, U24
U3
POWER PIN
3.3V?
NO
1. CHECK PC
2. CHECK SIGNAL CABLE
& D-SUB CONNECTOR
LINE
CHECK
R,G,B INPUT?
U3 PIN 87, 91, 95
NO
CHECK H-SYNC LINE
(D-SUB→U6→MICOM
→U3 PIN150)
CHECK
H-SYNC INPUT
U3 PIN 150?
NO
YES
YES
YES
NO RASTER
(OSD IS DISPLAYED)
4. NO RASTER (OSD IS DISPLAYED) – gmzanl