LC-30HV4E (serv.man10). Troubleshooting table - Sharp TV Service Manual (repair manual). Page 5

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
.).
Page of 10
Display

Click on the first or last page to see other LC-30HV4E (serv.man10) service manuals if exist.