Sharp 27DV-S100 Service Manual page 57

No video
NO
AV SW (IC1301), video signal (1Vp-p)
input to pin(63) (Tuner), pin(8) (LINE1),
pin(15) (LINE2) ?
YES
NO
AV SW (IC1301), video signal (2Vp-p)
output from pin(53) ?
YES
NO
Y/C separation (IC1401), video signal
(0.75Vp-p) input to pin(4) ?
YES
NO
Y/C separation (IC1401), Y-Signal
(1.30Vp-p) output from pin(15) ?
YES
NO
Video chroma (IC4401), Y-signal input
to pin(15) ?
YES
NO
Video chroma (IC4401), Y-signal output
from pin(4) and input to pin(53)?
YES
NO
Video chroma (IC4401), R,G,B-signal
output from pin(43), (42), (41) ?
YES
NO
RGB amp (IC8850), RGB-signal input
to pin(1), (2), (3) ?
YES
NO
RGB amp (IC8850), RGB-signal output
from pin(9), (8), (7) ?
YES
Check the CRT screen control
FLOW CHART No.1-3
Check each line
Tuner TU1951 pin(19) output
LINE1 J1301
LINE2 J3801
Check IIC-Bus and +9V line pin(33),
(34) (IIC-Bus), pin(42) (+9V)
Check video signal line between
IC1301 and IC1401
NO
Y/C separation (IC1401), fsc
(3.58MHz) input to pin(10) ?
YES
Replace IC1401
Check between IC1301 and IC4401
Check Video chroma circuit
Check between Terminal PWB and
CRT PWB
Replace IC8850
No color
Y/C separation (IC1401), Y/C separation (IC1401),
NO
chroma signal output from 3.58MHz signal input to
pin(13) ? pin(10)?
YES
Video chroma (IC4401), NO
Check between IC1401
chroma signal input to
and IC4401
pin(13)?
YES
NO
Video chroma (IC4401)
3.58MHz signal output to
pin(1)?
Check between IC1401
and IC4401
NO
Video chroma (IC4401),
Check X-tal (X4801)
pin(10)=3.58MHz signal?
YES
Video chroma (IC4401),
pin(5), (6) output from B-Y, NO
Check color control of
R-Y signal and pin(52),
picture adjustment
(51) input to B-Y, R-Y
signal?
YES
Replace IC4401
FLOW CHART No.1-4
YES
Replace IC1401
NO
YES