VSX-1017AV-K
59
5
6
7
8
5
6
7
8
C
D
F
A
B
E
5.2 CIRCUIT DESCRIPTION
5.2.1 PROTECTION CIRCUIT SPECIFICATION
Protection Circuit Process List
DC Detection Circuit
Item
Purpose
Detection Method
Process
Warning Indication
Remarks
DC
detection
T
o detect amplifier damage
(defect status)
A process to protect speakers
(for protection of connected
external devices)
Detects when the DC
_
PR
OT
EC
T
port becomes
"
L
"
.
(Pin 7
2
of
I
C101)
T
urns muting on and
speaker relay off, then
turns off the power after
3
seconds.
T
hen flashes
MCACC indicator.
Flashing
"
AMP ERR
"
for
3
seconds.
O
nce detected and turned
the power off, input a key
never again.
I
f the
DC
_
DE
T
port becomes
"
H
"
within
3
seconds, the
unit returns to normal
condition automatically.
AMP
overload
T
o detect overloading
(abnormal status)
With low
-
load driving or a
short circuit of the speaker
terminals (for protection of the
amplifier)
Detects when the
O
L
_
DE
T
port
becomes
"
L
"
(checks by interrupt).
(Pin 17 of
I
C101)
T
urns muting on and
speaker relay off, and
immediately turns off the
power.
T
hen flashes
PHASE C
ONT
R
O
L
indicator.
N
one
O
verheat
detection
Self reset type protection
feature by temperature
-
rise of
heat sink
Detects when the
T
EMP
2
port
becomes
"
H
"
.
(Pin
44
of
I
C
23
01)
T
urns muting on and
speaker relay off, then
turns off the power after
3
seconds.
Flashing
"O
VERHEA
T"
for
3
seconds.
I
f the
T
EMP
2
port
becomes
"
L
"
within
3
seconds, the unit returns
to normal condition
automatically.
1
2
V
trigger
failure
detection
T
o detect the shortcircuit of
1
2
V trigger output (load more
than 50mA) (for protection of
the amplifier)
Detects when the 1
2
VDE
T
port
decomes
"
H
"
.
(Pin
4
1 of
I
C
23
01)
T
urns 1
2
V trigger output
to off.
Flashing
"
1
2
V
T
RG ERR
"
Continue showing warning.
Release the FL indication
by switching the
IN
PU
T
SEL or the turns the power
off.
R571
4
R57
2
1
Q557
2
GAMP
G
N
DU
Q5571
I
C5
3
01
I
C5
3
0
2
R5
34
1
O
U
T
PU
T
DC DE
T
EC
TO
R
R ch
C ch
SR ch
SBR ch
SL ch
SBL ch
+VL
V+5UM
N
ormal: High (5V)
DC det: Low (0V)
+DC detection: Q5571 base is
"
H
"
.
→
Collector of Q5571 and Q557
2
are
"
L
"
.
-
DC detection: Q557
2
emitter is minus to the base.
→
Collector of Q5571 and Q557
2
are
"
L
"
.
-
VL
R5
342
R5
44
1
R5
442
R55
4
1
R55
42
R5
32
5
R5
32
7
R5
32
6
R5571
R56
4
1
R56
42
C5571
R170
C118
D118
FFC J
43
UC
O
M
I
C101
7
2
C
N
5
3
0
2
-
5
C
N
5
3
01
-
8
C
N
570
2
-
7
C
N
570
3
-
15
C
N
560
2
-
6
C
N
5601
-
8
L ch
R50
4
1
R50
42
R51
4
1
R51
42
R5
24
1
R5
242
C
N
5001
-
6
C
N
10
3
-
5
P
O
WER AMP
-
R ASSY
P
O
WER AMP
-
L ASSY
P
O
WER
PR
OT
EC
T
ASSY
P
O
WER
AMP
IN
ASSY
MA
IN
C
ONT
R
O
L ASSY
C
AG
AJ
AI
AD
