Trouble Shooting Table - Sharp SX68JF100 Service Manual

TROUBLE SHOOTING TABLE

Circuits to be checked:
» IC1500, 1501 and its NO VERTICAL SCAN
peripheral circuit
Check the voltage at pin (6) of IC1501 and
Normal
pin (6) of IC1500.
Check vertical trigger pulse at pin (31) of IC2801.
Normal Abnormal
Check IC1500, IC1501 Check IC2801 and its
and related circuits peripheral parts.
Note 1: Make sure that not for the horizontal centering mode.
Turn on the service mode. (Short J351 and J352.)
Then when you press "- / --" key on the remote you
can get in the horizontal centering mode.
Note 2: The vertical sync signal must be fed to pin (2) of
IC1000 in oder not to activate the vertical no-scan
protector.
Take this measure with the protector circuit for the
troubleshooting on the following pages.
Abnormal
Check L1500, D1576 and
R1576.
13-1
TROUBLE SHOOTING TABLE
Circuits to be checked:
» Power circuit.
» Video circuit.
» Protector cirucit.
» Peripheral circuit of
Bus Line.
Yes
Check connector (KY) and (H) of CRT.
Normal Abnormal
Check IC3801,
Check IC2801.
IC3802 and
IC3803.
D1202 (POWER LED) turns on and
off.
(Bus error)
See many often
D1202 flashes
in red.
This indicates
which IC to
check up.
(Continued)
NO RASTER
No
Does RY2700 turn on?
Turns on, but soon turns off.
Does D1202 (POWER LED) turn on?
Yes (RED)
Yes No
Check the
Check protector
power circuit
circuit and its
consisting of
related parts (2)
IC1701, IC1702,
of IC1000
D1700 and etc.
V-PULSE.
B
13-2
A