Protection Circuit Specification - Pioneer VSX-2016AV-S Service Manual

1

7.1.2 PROTECTION CIRCUIT SPECIFICATION

A
Protection Circuit Process List
Item Purpose
To detect amplifier damage
(defect status)
A process to protect speakers
DC
(for protection of connected
detection
external devices)
To detect overloading
(abnormal status)
AMP
With low-load driving or a
overload
B
short circuit of the speaker
terminals (for protection of the
amplifier)
Self reset type protection
Overheat
feature by temperature-rise of
detection
heat sink
12V To detect the shortcircuit of
trigger 12V trigger output (load more
failure than 50mA) (for protection of
detection the amplifier)
C
DC Detection Circuit
AG
POWER AMP-R ASSY
+VL
D
IC5301
R5341
OUTPUT
R ch
R5342
IC5302
E
SR ch
-VL
SBR ch
+DC detection: Q5571 base is "H".
→ Collector of Q5571 and Q5572 are "L".
-DC detection: Q5572 emitter is minus to the base.
→ Collector of Q5571 and Q5572 are "L".
F
198
1
2
Detection Method
Detects when the DC_PROTECT
port becomes "L".
(Pin 120 of IC101)
Detects when the OL_DET port
becomes "L" (checks by interrupt).
(Pin 28 of IC101)
Detects when the TEMP2 port
becomes "H" .
(Pin 44 of IC2301)
Detects when the 12VDET port
decoms "H".
(Pin 44 of IC2301)
DC DETECTOR
CN5302 CN5702
-5
Q5571
Q5572
GAMP
R5441
R5442
CN5301 CN5602
-8 -6
R5541
R5542
POWER
AMP IN ASSY
VSX-2016AV-S
2
3
Process
Turns muting on and
speaker relay off, then
turns off the power after 3
seconds. Then flashes
MCACC indicator.
Turns muting on and
speaker relay off, and
immediately turns off the
power. Then flashes
PHASE CONTROL
indicator.
Turns muting on and
speaker relay off, then
turns off the power after 3
seconds.
Turns 12V trigger output
to off.
AJ
POWER
PROTECT
C
ASSY
V+5UM
R5721
CN5703
CN103
-7 -15
-5
FFC J43
R5714
GNDU
CN5601 CN5001
-8 -6
C ch L ch SL ch
AI AD
POWER AMP-L ASSY
3
4
Warning Indication Remarks
Once detected and turned
the power off, input a key
Flashing "AMP ERR" for
never again. If the
3 seconds.
DC_DET port becomes
"H" within 3 seconds, the
unit returns to normal
condition automatically.
None
If the TEMP2 port
becomes "L" within 3
Flashing "OVERHEAT"
seconds, the unit returns
for 3 seconds.
to normal condition
automatically.
Continue showing
warning.
Release the FL indication
Flashing "12V ERR"
by switching the INPUT
SEL or the turns the power
off.
MAIN CONTROL ASSY
Normal: High (5V) UCOM
DC det: Low (0V)
IC101
120
SBL ch
4