Sharp AQUOS LC-37AD1E, Service Manual

Page: 52 / 262

52
LC-37AD1E
YES
No
YES
YES
YES
No
YES
No No
No No
Check if the internal/external
switching relay (RY3901)
functions correctly.
Is the output signal from the
1-bit amplifier applied to
P3903?
Perform checking around
IC2004, IC3804 and the 1-
bit amplifier.
Are the MUTE circuits
(Q3804 and Q3805)
operating?
Is the audio signal applied to
pin (7) (L-IN) and pin (9) (R-
IN) of P3804?
Perform checking
around IC3803 and
IC3808.
Check for the AVC
System side for output.
Is the audio signal applied to
pin (13) and pin (20) of
SC2202 on the Monitor PWB?
Perform checking around Q2012 and
Q2014 and check the wire between
Monitor PWB and Audio PWB.
Check if 5V is supplied to the power
regulator circuit (IC3812 and IC3816)
and pin (2) of P3804.
Is power supplied to each IC
on the AUDIO PWB?
Is the audio signal applied
to pin (13) and pin (15) of
P3803?
No sound comes out. (Checking with the AVC
System connected)
YES
No
No
YES
YES
No
YES
Check the connection of the high-voltage
(pin (2)) wire on the side of the blown
fuse and check that of the counterpart
high-voltage (pin (2)) wire of the
fluorescent lamp on the opposite side.
The backlight does not go on.
Is any of the fuses of
F7501-F7504,
F7551-F7553,
F7611-F7614 and
F7641-F7643 blown?
Is the control signal applied to
pin (2) (OFL1) and pin (3)
(OFL2) of P7506 and P7616? Is the harness connected correctly
between the Monitor PWB and
Inverter-1 and -3 PWBs?
Check the peripheral circuitry of
IC4501 of the Monitor PWB and
check the operation of Q7704
and Q7705.
Is power supplied to each
Inverter PWB?
Check the wire connecting the Inverter-1 and -3 PWBs, the
wire connecting the Inverter-2 and -4 PWBs, the board-to-
board between the Inverter-1 and -2, and the board-to-
board between the Inverter-3 and -4.
Check the 15V output on the
Power PWB.
Check the inverter
circuit downstream
from the blown fuse. Check the counterpart
inverter circuit on the
opposite side.