LL-T15G3 (serv.man14). Complete - Sharp Monitor Service Manual (repair manual). Page 10

LL-T15G3

TROUBLESHOOTING

4 – 1

No power supply

Does LED turns on in green 
when power switch is turned 
on?

No

No

No

No

No

No

LED turns on in red?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

*  Check LED for breakage.
*  Check key cable for disconnection.

No output +5V, 12V from

power supply unit.

Yes

Replace power supply unit.

Replace any unit (main PWB, SW PWB, cable) 
which shows any defect, with a new one.

1) PC is turned off?
2) RGB cable is disconnected?
3) Synchronizing signal is output from RGB 

cable?

Check whether the unit is in power save 
mode (synchronizing signal is not input.).

Synchronizing signal is input to main PWB?

Replace RGB cable 
with a new one.

LED turns on in orange?

Check power input system.

1) Power supply PWB
   *  Normal?
   *  Connected properly?
2) Blown out fuse (F1)?
3) Check +5VX, 3.3VX, 3.3VA, VDD, VD
    and VLCD are output?
4) LED
   *  Check LED for breakage.
   *  Check the path between P5 and U6.
   *  Check the cable for disconnection.

Replace any defective unit.
[ 1) Power supply PWB, 2) Main PWB, 
3) Switch PWB ] with a new one.

Backlight turns ON?

Check for RGB cable input 
signal.

Replace RGB cable.

Check each pin terminal 
of P3.

Normal

Normal

Normal

Defective

Defective

*  Check inverter PWB unit.
Note: Use caution when checking output 

side because it has a high voltage. 

Replace LCD module lamp with 
a new one.

Replace inverter PWB 
unit with a new one.

A