Sylvania 6842THG Service Manual page 39

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?
When inputting to Video 1 In jack (AUDIO(L/R)).
IC 452 Pin (13) AUDIO1(L)
IC 451 Pin (13) AUDIO1(R)
When inputting to Video 2 In jack (AUDIO(L/R)).
IC 452 Pin (14) AUDIO2(L)
IC 451 Pin (14) AUDIO2(R)
When inputting to component 1 jack (AUDIO(L/R)).
IC 452 Pin (1) AUDIO3(L)
IC 451 Pin (1) AUDIO3(R)
When inputting to component 2 jack (AUDIO(L/R)).
IC 452 Pin (5) AUDIO4(L)
IC 451 Pin (5) AUDIO4(R)
When inputting to HDMI In jack (AUDIO(L/R)).
IC 452 Pin (2) AUDIO5(L)
IC 451 Pin (2) AUDIO5(R)
When inputting to ANT. In jack.
IC 452 Pin (15) AUDIO6(L)
IC 451 Pin (15) AUDIO6(R)
Is input switching signal inputted to each pins on
IC451 and IC452?
Pin (11)
Video 1 L
Video 2 L
Component 1 H
Component 2 H
HDMI L
TUNER L
Is audio signal outputted to each pins on IC451
and IC452?
IC452 Pin (3) L-CH
IC451 Pin (3) R-CH
Is audio signal inputted to each pins on CN113?
CN113 Pin (19) L-CH
CN113 Pin (18) R-CH
Replace the Digital CBA.
Yes
Pin (10) Pin (9)
L L
L H
L L
L H
H H
H L
Yes
Yes
Yes
Check lines between Pin (13) on IC452 and
JK701, between Pin (13) on IC451 and JK701,
No
and service it if defective.
Check lines between Pin (14) on IC452 and
JK705, between Pin (14) on IC451 and JK706,
No
and service it if defective.
Check lines between Pin (1) on IC452 and JK703,
No
between Pin (1) on IC451 and JK703, and service
it if defective.
No
Check lines between Pin (5) on IC452 and JK704,
between Pin (5) on IC451 and JK704, and service
it if defective.
No
Replace the Digital CBA.
No
Replace the Digital CBA.
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.
No
Pin (9) on IC451,IC452
Pin (10) on IC451,IC452
Pin (11) on IC451,IC452
Check +12V line and service it if defective.
No
Is +12V voltage inputted to Pin (16) on IC451 and
No
IC452?
Yes
Replace IC451 or IC452.
Check lines between Pin (3) on IC452 and
No
Pin (19) on CN113, between Pin (3) on IC451 and
Pin (18) on CN113, and service it if defective.
Pin (3) on IC452
Pin (3) on IC451
1-8-6
Pin (2) on CN112
Pin (3) on CN112
Pin (4) on CN112
Pin (19) on CN113
Pin (18) on CN113
L0700TR