Sharp LC-37XD10, Service Manual

Page: 41 / 190

LC-37XD10E/RU
4 – 8
DTV troubleshooting 2
No video output during
DTV reception. Colors
of Images are not right. No audio output during
DTV reception. Sound
is low.
D-TUNER UNIT:
Is data FED[0:7] sent
from pins
(3),(4),(5),(6),(8),(9),
(10) and (11) of P202? NO Check R272 and R273. DIGITAL UNIT:
Is audio signal fed to
pins (5) and (10) of
IC4604 (OP-AMP)? NO Check R4002(AD2pin)
and IC4001(D-Proces-
sor).
YES YES
DIGITAL UNIT:
Are video signals (R/G/
B,CVBS) sent from
C4639/C4640/C4641/
C4625? NO Check
R4011(AC8pin),R4013(A
C9pin) and IC4001(D-Pro-
cessor). Is audio signal sent
from pins (7) and (8) of
IC4604(OP-AMP)? NO Check power supply of
IC4604(OP-AMP) and its
peripheral circuits.
YES YES
Are video signals (R/G/
B,CVBS) send from the
C4636/C4637/C4638
and emitters of Q4607? NO Check Q4601-
Q4605,Q4607 and their
peripheral circuits. MAIN UNIT:
Is audio signal sent to
pin (3) and (13) of
IC2704 (SW)? NO Check power supply and
control signal of pins (9)
and (10) of IC2704(SW)
and audio signal input of
pins (4) and (11) of
IC2704.
YES YES
MAIN UNIT:
Are video signals (R/G/
B,CVBS) fed from pins
(AA18),(AB18),(Y18)
and (AA21) of IC3002? Perform the same
check as the tuner (U/
V) reception. .
YES
Are scrambled images
not displyed? YES DIGITAL UNIT:
Check 5V output of pin (1)
of IC4702.
Check 5V of pin (6) of
Q4401.
NO
Perform the same
check as the tuner (U/V)
reception.