Samsung 2493HM

4-4
4. Troubleshooting
4-3. When a blank screen is displayed (Analog)
Symptom
The LED power is on but no picture is displayed on the screen when the D-SUB cable is
connected
-
Major checkpoints
Check if the D-SUB cable has been connected.
Check if the LVDS cable has been connected properly to the LCD panel.
Check if the Inverter board has been connected properly to the lamp connector of the LCD panel.
-
-
-
Diagnostics
Main Board Front
③ CN400
① X300
⑤ IC600
④ IC300
③ R106,R109
②R117,R120,R121
Yes
①
Check the signal cables and
their connections.
Yes
Check and replace related
circuits if necessary.
No
Check if X300 is oscillating normally.
Check if R, G and B inputs are
measured at R117, R120, and R121.
Check the input part.
No
Yes
Check if Hsync and Vsync are
measured at R106 and R109.
Check the input part.
No
Yes
Check if Hsync and Vsync are measured
at pins AF12 and E12 of IC300.
Check the circuit around
IC300.
No
②
Yes
Check if DC 5V is measured at pin 5 of
IC600.
No
Check the input part.
③
Yes
Check if the output signal appears at
pins 8 to 30 of CN400.
No
Check the circuit around
IC300.
Yes
Replace the LCD panel.
④
⑤
⑥
Caution Check only after checking if the power is disconnected at the SMPS.