Read Sharp LC-19A1E (serv.man4) Service Manual online
LC-19A1E-BK/WH
4 – 2
No power supplied (Front LED does not turn on). Power switched on but no power supplied. (Front LED does not turn Red
→ Green)
YES
Remove SC1204 connector of MAIN unit. When you input 3.3V
to pin (9) of SC1204 connector, check whether UR12V are out-
putted to pin (13) to (15).
to pin (9) of SC1204 connector, check whether UR12V are out-
putted to pin (13) to (15).
NO
Exchange the power supply units.
YES
Check whether there is any loose connection of a connector
(CN2 and SC1204).
(CN2 and SC1204).
YES
Check the item of the check list of POW (2).
(Check whether BU3.3V is outputted.)
(Check whether BU3.3V is outputted.)
Power supply (troubleshooting): A power supply does not come to each main circuit/IC. (1)
The power supply of TUNER (TU501) does not operate.
Checklist
1) The check of the front page POW (1) is completed.
1) The check of the front page POW (1) is completed.
• • • UR12V is output to SC1204 (MAIN-PCB).
(If UR12V is not output, confirm the POW (1) again and repair.)
2) Check that BU3.3V is supplied to IC2002 (SUB-MICON), and the AC-CTL signal H is output from 35pin within a MAIN board.
(If BU3.3V is not supplied, check IC2004 (BU3.3V-REG) and a periferal circuit.)
3) Refer to attached sheet Power-Block diagram.
Is B5V supplied to pin (3) of TUNER (TU501)?
YES
Check the soldering of TUNER (TU501), confirm I2C-LINE or
exchange it.
exchange it.
NO
Is 5.6V supplied to pin (1) of IC504 (B5V-REG)?
YES
Check the soldering of IC504 or exchange it.
NO
NO
Check whether the POWER-CTL signal is input to pin
(7) of IC505.
(7) of IC505.
YES
Check the soldering of IC504 or exchange it.
Is UR12V supplied to pin (2) of IC505 (5.6V-REG)?
YES
Check the soldering of IC505 or exchange it.
NO
Check between pin (13) of SC1204 to pin (2) of IC505 (5.6V-
REG). (CONNECTOR SC1202/P501)
REG). (CONNECTOR SC1202/P501)
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