Pioneer VSX-1018AH-K Service Manual page 63

5
[2] Protection Circuit Process List (XPROTECT)
Item Purpose
AMP power supply circuit and
Transformer short circuit
detect. (defect status)
XPROTECT
Observe CN5701 pin3 or pin5
voltage, VL+ and VL-.
XPROTECT Circuit
R
POWER AMP ASSY
CN5701 CN5701
-5 -3
D5721 D5722
1SS352
1SS352
GAMP
B
MAIN ASSY
UCOM
IC101
102
5
6
Detection Method
Detects when the XPROTECT
port becomes "L".
(Pin 102 of IC101)
Short circuit detect:
Transformer
Q5781
DTC124EUA
CN108
-15
V+5US
C421
0.047u/25
GNDU
6
7
Process Warning Indication
Turns muting on and
speaker relay off, and
None
immediately turns off the
power. Then flashes
DIGITAL PRECISION
PROCESSING indicator.
Short circuit detect:
AMP power supply circuit (VL)
VL+
V+5UM
Q5783
DTA124EUA
Q5782
DTC124EUA
GNDU
CN5803
-9
CN4808
-9
E
INTERFACE ASSY
CN4803
-15
VSX-LX51
7
8
Remarks
Once detected and turned
the power off, input a key
never again.
V+5UM
Q5784
DTA124EUA
R5784
Q5785
DTC124EUA
47k
UDZS7R5(B)
VL-
GNDU
D5782
GNDU
8
A
B
C
D
E
F
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