Read Sharp LC-30HV4E (serv.man10) Service Manual online
56
LC-30HV4E
Check the PC I/F unit.
A
VC System
<When component/RGB signal is received>
No image (5)
No RGB image on INPUT1
Has "INPUT1" been selected
on the Input Select screen?
Are RGB signals applied to
pins 63, 59 and 61 of IC1401
(A
V switch)?
Select INPUT1 RGB on
the Input Select screen.
Check lines and devices
between pins 15/1
1/7 of
INPUT1 (SC1
101) and
pins 63/59/61 of IC1301.
No RGB image on INPUT3
Has "INPUT3" been selected
on the Input Select screen?
NO
NO
YES
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
YES
YES
NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
Select INPUT3 RGB on the
Input Select screen.
Are RGB signals applied to
pins 9, 5 and 7 of IC1401
(A
V switch)?
Check lines and devices
between pins 15/1
1/7 of
INPUT3 (SC1
102) and pins
9/5/7 of IC1301.
No component image on INPUT3
Has "INPUT3" been
selected on the Input Select
screen?
Select INPUT3
COMPONENT
on the Input
Select screen.
Are RGB signals applied to
pins 5, 17 and 19 of
IC1401 (A
V switch)?
Check lines and devices
between pins 8/26/17 of
INPUT3 (J1
101) and pins
15/17/19 of IC1301.
Are the main video signal, pass signal and sub video signal sent from pins 34, 38 and 36 of IC1401 respectively?
Are
Y,
Cb and Cr signals applied
to pins 19, 18 and 17 of IC801
(main video chroma) respectively?
<Main 525i system>
<Pass 525P/1
125i/750P
system>
Check lines and devices between
pins 46/50/48 of IC1401 and pins
19/18/17 of IC801.
Are the main
Y
, Cb and Cr
signals sent from pins 21, 22
and 23 of IC801 respectively?
Check IB801 (main video
chroma) and its peripheral
circuits.
Are the main
Y
, Cb and Cr
signals applied to pins 69, 68
and 67 of IC803 respectively?
Check lines and devices
between IC801 and IC803.
(IC814, Q814-5, etc.)
Are
Y
, Cb and Cr signals applied
to pins 5, 4 and 3 of IC803
(RGB decoder) respectively?
Check lines and devices
between pins34/38/36 of
IC1401 and pins 5/4/3 of IC803.
Are the main R, G and Br
signals sent from pins 35, 37
and 39 of IC803 respectively?
Check IC803 (RGB decoder)
and its peripheral circuits.
Are the main R, G and Br
signals applied to pins 3, 7 and
10 of IC810 (6.7/30 MHz L.P
.F
.)
respectively?
Check lines and devices
between IC803 and FL810.
(Q801-3 etc.)
Are the main R, G and Br
signals sent from pins 19, 15
and 12 of IC810 respectively?
The cutof
f frequency of FL810
(L.P
.F
.) is switched as follows
depending on the input
signals:
Status of pin 17 for setting the
cutof
f frequency of FL810 (6.7/30
MHz L.P
.F
.)
<525i system>: High
<525P/1
1
25i/750P
system>: Low
Check FL810 (6.7/30 MHZ L.P
.F
.)
and its peripheral circuits.
<Sub system>
Are
Y
, Cb and Cr signals
applied to pins 19, 18 and 17
of IC802 (sub video chroma)
respectively?
Check IC1401 (A
V switch)
and its peripheral circuits.
Check lines and devices
between pins 40/44/42 of IC
1401 and pins 19/18/17 of
IC802.
Are the sub
Y,
Cb and Cr
signals sent from pins 21, 22
and 23 of IC802 respectively?
Check IC802 (sub video chroma)
and its peripheral circuits.
Are the sub
Y,
Cb and Cr signals
applied to Q901-2, Q903-4 and
Q905-6 (6.7 MHz L.P
.F
.)
respectively?
Check lines and devices between
IC802 and Q901-2/Q903-4/Q905-
6 (6.7 MHz L.P
.F
.).
Are the sub R, G and B signals
sent from Q901-2, Q903-4 and
Q905-6 (6.7 MHz L.P
.F
.)
respectively?
Check peripherals of Q901-
2/Q903-4/Q905-6 (6.7 MHz
L.P
.F
.).
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