LL-T181A (serv.man11). Troubleshooting, triming and processing lead wires - Sharp Monitor Service Manual (repair manual). Page 2

Does backlight come on?

No

Yes

Check D-sub PWB.

Normal

Abnormal

Replace D-sub PWB.

Replace inverter PWB unit.

Replace LCD module.

• Check inverter PWB unit.
Note: Pay attention to a high voltage when
checking output side (1800 Vrms at starting).

Check CN1 (CN2) pin terminals.
Pin No.    Name                 Check voltage
1              VIN                     +12V
2              GND                       0V
3              BRT1 (BRT2)         0V
4              ALM1 (ALM2)       +5V
5              ON/OFF               +5V

1

2

Abnormal

Normal

Abnormal

Normal

Check output circuit to CN1 (CN2).
  1  When VIN is NG:
      (1) Main PWB F1, F2 defective, or
      (2) DC jack PWB F1 defective
  2  When BRT is NG
      Operation PWB defective
  3  When ON/OFF is NG
     (1) DC jack PWB F1 defective, or
     (2) Main PWB D3 defective

Replace any defective unit.
(1) of  1 , (2) of  3 : Replace main PWB.
 2 :                          Replace switch PWB.
(2) of  1 , (1) of  3 : Replace DC jack PWB.