Pioneer VSX-LX53 Service Manual page 51

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[2] Protection Circuit Process List (XPROTECT)
Item
AMP power supply circuit and
Transformer short circuit
detect. (defect status)
XPROTECT
Observe CN5701 pin3 or pin5
voltage, VL+ and VL-.
XPROTECT Circuit
H
POWER AMP ASSY
CN5701
-3
D5721
1SS352
TE
L 13942296513
J
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Purpose Detection Method
Detects when the XPROTECT
port becomes "L".
(Pin 83 of IC3001)
CN5701
-5
Short circuit detect:
Transformer
D5722
1SS352
GAMP
LTC124EUB
DISPLAY ASSY
UCOM
IC3001
83
C3016
0.047u/50
GNDU
x ao
y
i
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Process
Turns muting on and
speaker relay off, and
immediately turns off the
power. Then flashes
MCACC indicator.
Short circuit detect:
AMP power supply circuit (VL)
V+5_UST
V+5_UST
Q5783
LTA124EUB
Q5782
LTC124EUB
Q Q
3 6 7 1 3
Q5781
GNDU
CN5805
-15
CN602
-17
E
DIGITAL MAIN ASSY
CN601
-27
CN3001
-13
V+5_ST
u163
.
VSX-LX53
6
7
2 9 9 4 2 8
Warning Indication
Once detected and turned
the power off, the power
None
cannot be turned on again.
(*)
(*) To restore the previous status, follow the procedure
described in "How to Enter Release Mode" (P.54)
then turn the unit back on.
VL+
V+5_UST
Q5784
LTA124EUB
R5784
47k
UDZS7R5(B)
VL-
GNDU
D5782
1 5 0 5 8 2 9 9 4
m
co
7
8
9 9
A
Remarks
B
Q5785
C
LTC124EUB
GNDU
2 8 9 9
D
E
F
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