LL-T2015 - Sharp Monitor Service Manual (repair manual). Page 13

LL-T2015-B/H

TROUBLESHOOTING

4 – 1

(Yes)

(Yes)

(Yes)

(Yes)

(Yes)

Green LED comes on when the power button is 
pressed?

The screen is displayed properly in each video 
mode?

AC cable is connected to the power supply 
unit?

Input signal port is the one to which analog 
signal cable is connected?

Test terminals LD405, LD406, and LD407 are 
DC+3.3V?

Test terminal LD515 changes its level when 
POWER switch is turned on and off?

Press INPUT key to switch over to the 
correct input signal port.

Check DC+5V power supply line (DV5) and 
POWER_CTL1 signal and circuits  around 
Q804.

Check the connection line of LD515, and 
check the CN501, SW PWB and cable.

Remove the analog signal cable. After a short 
while time, the LED color changes form green 
to orange. 

(Yes)

(Yes)

(No)

(No)

(Yes)

(Yes)

(No)

(No)

(No)

(Yes)

(Yes)

(No)

(No)

(No)

(No)

(No)

(Yes)

(No)

(Yes)

(Yes)

(No)

(No)

(No)

Perform  1

B/L is lit?

No error.

Check AC cable connection.

Check power supply unit switch.

Check circuits around IC503. 

Check circuits around IC802. 

Check circuits around IC401.

Check RESET circuit around IC505.

Check IC502 and clock circuit around X501.

The power supply unit is switched on?

Test terminal LD808 is DC+5V?

Test terminal LD809 is DC+5V? 

4th pin of IC505 is in H level (DC+3.3 V)?

C504-side terminal signal of X501 is normal?

Test terminal LD533 is DC+3.3V?

(Yes)

(No)

Check circuits around IC803. 

Test terminal LD811 is DC+3.3V?

1

Perform  2

Perform  3

Perform  4

Check whether the following cables are connected correctly.
In addition, check whether the PCs video mode is properly set to the signal timing which meets this machine.

Attached cables
  Dedicated AC adapter
  Dedicated analog signal cable (D-sub15 pin or DVI-A cable use.)
  Dedicated digital signal cable (DVI-D cable)