SERVICE MANUAL
Document No
Date of Origin
Date of REV
51-L-DSR004
98-10-21
PAGE REV.
0
PAGE
31 /102
S-00-005(96.03.27)
REV.1
7-5. No Power
7-5-1. Check the input AC voltage
7-5-2. Check fuse. (Rating
250V T2A)
7-5-3. Check the SMPS output voltages.(Refer
to page for pin discription)
7-5-4. if there are no power then go to 7-4
7-6. Video
7-6-1. Press 'venc 0 39' command
using PC terminal
7-6-2. Check U750 pin 11, for composite
video signal
if there is no composite
video output goto 7-6-6
Figure 7-6-2. composite
video(1V
p-p) signal wave form
7-6-3. Check U752 pin 14, if there is no composite
video output then
check pin 16 VCC Voltage.
if there is 5V then Replace
the U752 IC's
7-6-4. Check the test point TP917, if there is no composite
video signal
(2V p-p) then check pin 54 of U901 VCC Voltage.
it should always be
+12V, if no problem
Replace
U901 IC's
7-6-5. Check the test point TP918, if there is no composite
video signal
then Replace
Q911 else goto 7-6-8
7-6-6. Continually
Check U750 pin 13, 16, 24, 26, 27 for video encoder
control
signal and check pin 15, 21 VCC voltage.
pin 13, 16
will
be about 1.1V. If there is no more problem,
Replace
U750 IC's
20 uS /
500mV div