Sharp LC-19D1E/S-BK/WH, Service Manual

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LC-19D1E/S-BK/WH
4 – 1
LC19D1E-BK
Service Manual
CHAPTER 4.
TROUBLESHOOTING TABLE
[1] TROUBLESHOOTING TABLE
No power supplied (Front LED does not turn on). Power switched on but no power supplied. (Front LED does not turn Red
→
Green )
YES
Are the power cord connector correctly connected to the body? NO Reconnect the power cord correctly and switch on the power
again.
YES
Remove CN2 connector of POWER unit. When you input 3.3V to
pin(9) of CN2 connector , check whether UR12V are outputted 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).
YES
Is the AC-CTL signal (H) input to pin (9) of CN2 connector? NO Is the signal of AC-CTL:H output from 35 pins of IC2002(SUB-
MICON) in the MAIN UNIT?
YES
NO
Check a power circuit of IC2002 and periferal circuit.
Please exchange IC2002 when still not repaired.
Is BU3.3V output to connector P101 (1) pin of the R/C unit and
the P2003 (1) pin of the MAIN unit ? NO Please check whether IC2004 and BU3.3V line short-circuit.
(IC2002,IC2001,IC2003,IC2006,P2003-1pin,BU3.3V-line)
YES
Please check of POWER-LED (D103) of a R/C unit, Q101, Q102,
or peripheral circuits.
Power supply (troubleshooting): A power supply does not come to each main circuit or IC. (1)
The power supply of TUNER (TU501) does not operate.
Checklist
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(1) of TUNER (TU501) ? NO Check whether regulator IC of IC504 and IC505 is normal.
YES
Is B5V(CONT) supplied to pin(11) of TUNER (TU501) ? YES Check regulator IC of IC505. and check whether the POWER-
CTL signal is inputted into pin(7) of IC505.
NO
Is UR12V supplied to pin(2) of IC505 (5.6V-REG) ? YES Check the the soldering confirmation of IC207 or exchange it.
NO
Check whether other pins of TUNER (TU501) to be short-cir-
cuited.
If normal,exchange TUNER(s).