27
VSX-918V-K
5
6
7
8
5
6
7
8
A
B
C
D
E
F
5. DIAGNOSIS
5.1 DIAGNOSIS FLOWCHART
•
W
hen a sound is not out in the multi-CH signal playback mode or surround mode with the COAX, OPT, USB or HDMI input.
(SurroundBack is not output by setting.)
• Suppose CR to be normal contact and that is not damaged.
• This shows failure analysis of DSP Block.
Step 4: 3 V to 5 V conversion
Step 1: MUTE pin
IC351
Do
convert 3
V
into
5
V
for input?
Replace IC201.
Replace IC1.
Replace IC2.
To Step 2
To Step 4
To Step 5
Step 0: Preliminary confirmation
Confirm the following items before checking
Do screws
of COAX Jack
securely tighten
?
Tighten screws securely.
N
o
Yes
To Step 1
IC201 (Pin 54)
Is the
voltage of output
signal 0
V
?
N
o
Replace IC351.
N
o
Yes
MUTE
Troubleshooting for all destination
[1] DSP TROUBLESHOOTING
Step 3: Regulator IC
Check the IC1 and
REGULATOR Assy.
IC1 (Pin 4)
Is the
voltage of around
5
V
to 5.3
V
input?
N
o
Yes
(to chassis)
IC2 (Pin 5)
Is the
voltage of 1.25
V
output?
N
o
(to chassis)
IC1 (Pin 5)
Is the
voltage of 3.3
V
output?
N
o
Yes
Yes
Yes
IC341
Do
convert 3
V
into
5
V
for input?
Replace IC341.
N
o
Yes
(to chassis)
Part shape and Pin arrangement
of IC1 and IC2
Step 2: BtoB connector and FFC
C
N
1, C
N
2
Are the
connectors securely
inserted?
Turn the power off and
insert the connectors
securely.
N
o
Yes
C
N
3
Is the
FFC securely
inserted?
Turn the power off and
insert the connectors
securely.
N
o
Yes
To Step 3
BtoB connector
FFC
