Sylvania 6842THG, Service Manual

Page: 39 / 123

1-8-6 L0700TR
FLOW CHART NO. 3
Audio is not outputted to audio output terminal normally.
[JK1405 (Analog audio output jack) and JK1403 (Digital audio output jack)]
Input audio signal.
Is audio signal inputted to each pins on IC451
and IC452?
IC452 Pin (13) AUDIO1(L)
IC451 Pin (13) AUDIO1(R)
IC452 Pin (14) AUDIO2(L)
IC451 Pin (14) AUDIO2(R)
IC452 Pin (1) AUDIO3(L)
IC451 Pin (1) AUDIO3(R)
No
No
No
No
No
No
IC452 Pin (5) AUDIO4(L)
IC451 Pin (5) AUDIO4(R)
Check lines between Pin (13) on IC452 and
JK701, between Pin (13) on IC451 and JK701,
and service it if defective.
Check lines between Pin (14) on IC452 and
JK705, between Pin (14) on IC451 and JK706,
and service it if defective.
Check lines between Pin (1) on IC452 and JK703,
between Pin (1) on IC451 and JK703, and service
it if defective.
Check lines between Pin (5) on IC452 and JK704,
between Pin (5) on IC451 and JK704, and service
it if defective.
When inputting to Video 1 In jack (AUDIO(L/R)).
When inputting to Video 2 In jack (AUDIO(L/R)).
When inputting to component 1 jack (AUDIO(L/R)).
When inputting to component 2 jack (AUDIO(L/R)).
IC452 Pin (2) AUDIO5(L)
IC451 Pin (2) AUDIO5(R)
When inputting to HDMI In jack (AUDIO(L/R)).
IC452 Pin (15) AUDIO6(L)
IC451 Pin (15) AUDIO6(R)
When inputting to ANT. In jack.
Pin (9) on IC451,IC452 Pin (2) on CN112
Pin (10) on IC451,IC452 Pin (3) on CN112
Pin (11) on IC451,IC452 Pin (4) on CN112
L
L
H
H
L
L
Video 1
Video 2
Component 1
Component 2
HDMI
TUNER
L
L
L
L
H
H
L
H
L
H
H
L
IC452 Pin (3) L-CH
IC451 Pin (3) R-CH
Is audio signal outputted to each pins on IC451
and IC452?
Is +12V voltage inputted to Pin (16) on IC451 and
IC452?
Is input switching signal inputted to each pins on
IC451 and IC452?
No
No
No
Yes
CN113 Pin (19) L-CH
CN113 Pin (18) R-CH
Is audio signal inputted to each pins on CN113?
No
Yes
Replace the Digital CBA.
Yes
Yes
Yes
Check lines between each pins on IC452 and
each pins on CN112, between each pins on
IC451 and each pins on CN112, and service it if
defective.
Pin (3) on IC452 Pin (19) on CN113
Pin (3) on IC451 Pin (18) on CN113
Check lines between Pin (3) on IC452 and
Pin (19) on CN113, between Pin (3) on IC451 and
Pin (18) on CN113, and service it if defective.
Check +12V line and service it if defective.
Replace IC451 or IC452.
Pin (11)
Pin (10) Pin (9)
Replace the Digital CBA.
Replace the Digital CBA.