Sharp AN-S422U, Service Manual

Page: 43 / 166

43
XG-V10WU
AN-SD1U/S422U
TROUBLE SHOOTING TABLE
(Continued)
Checking the chroma and Y signals of IC801
(RGB signal output)
Yes
No
Go to "Checking the video unit
circuit".
Yes
No
No
Are there signal inputs at pins (20)
(chroma signal) and (21) (Y signal)
of IC803?
Check IC803 and its peripheral
circuits.
Check IC6009 (3-D noise reduction
circuit) and its peripheral circuits.
Go to "Checking IC801 (RGB signal
output circuit)".
Yes
Are there signal inputs at pins (12),
(31) and (37) of SC401?
Are there output waveforms at pins
(7) of IC6014 (chroma signal) and
(7), (Y signal)of IC6015?
Check the IC6009 IC6010 and IC6011
switching and their peripheral circuits.
If there is no signal at pins (1) of
IC6014 and pin (5) of IC6015 and pin
(16) of IC6010 check 3-D noise
reduction circuit (IC6009).
Checking IC806 (3-D noise reduction circuit)
and its peripheral circuits
Yes
No
Check the buffer circuit of Q6007 thru
Q6011 as well as Q6013 thru Q6014.
Yes
No
Are there signal outputs at pins (55)
(Y signal) and (51)(chroma signal) of
IC8001?
Check IC6008, IC6010 (memory) and
their peripheral circuits.
Yes
No
Are there signal outputs at the
emitters of Q6010 (Y signal) and
Q6015 (chroma signal)?
Check the low-pass circuit around
Q6010, Q6012 and Q6015.
Check IC6011, IC6014, IC6015 and
IC801 (RGB signal output circuit).
Are there signal inputs at pins (40)
(Y signal) and (45)(chroma signal) of
IC6009?
No colour or unusual tone (NTSC, PAL, PALM, PALN)
Yes
No
Go back to the signal processing
block.
Yes
No
Check the oscillation of X801, X802,
X803 and X804 and their peripheral
circuits.
Check IC804, IC805 and their
peripheral circuits.
Are there signal outputs at pins
(46)(R-Y) and (45)(B-Y) of IC801?
Is there chroma signal input at pin
(20) of IC801?