LL-T15A3 (serv.man9). Complete - Sharp Monitor Service Manual (repair manual). Page 10

LL-T15A3

TROUBLESHOOTING

4 – 1

5) Check connector of power jack PWB 

for breakage. Check the cable for 
disconnection.

No power supply

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

No

No

No

No

No

Yes

Yes

Yes

Yes

Yes

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) AC adapter
   *  Normal?
   *  Connected properly?
2) Blown out fuse (F1) on main PWB?
3) EEPROM (U11) has +5V (VCC)?
4) LED
   *  Check LED for breakage.
   *  Check the path between J5 (5pin) 

and U11 (27pin) or J5 (6pin) and U11 
(26pin).

   *  Check the cable for disconnection.

Replace any defective unit.
[ 1) Adapter, 2) A Main PWB, 3) Switch 
PWB, 4) Power jack PWB] with a new one.

Backlight turns ON?

Check for RGB cable input 
signal.

Replace RGB cable.

Check each pin terminal 
of JP5.

Normal

Normal

Normal

Defective

Defective

Defective

Check output circuit to JP5.
1) If +12V is NG, replace main 

PWB.

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

side because it has a high voltage. 
(1400 Vrms when starting)

Replace LCD module lamp with 
a new one.

Replace inverter PWB 
unit with a new one.

A