Pioneer SC-37 Service Manual page 64

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QQ
3 7 63 1515 0
DIGITAL MAIN Power Supply Failure Detection
A
Item Purpose
DIGITAL Detect abnormal
MAIN voltage in the
power Digital Power
supply Supply circuit
failure
detection
F
DIGITAL MAIN ASSY
B
V+5R6_U
V+13_UN
R1999
4.7k
IC1900
PWRGD
C
IC1930
TE
L 13942296513
PGOOD
(*1) Conditions when XVDDERR becomes "L"
1. Q1997 turns ON : When V+6DDD becomes higher than the setting value, Q1997 becomes ON.
D
2. Q1998 turns ON : When V+5_DDD becomes higher than the setting value, Q1998 becomes ON.
3. Q1999 turns ON : When V+13_UN becomes lower than 3.8V, Q1999 becomes ON.
When PWRGD of IC1900 becomes low (V+5HD becomes lower than the setting value), Q1999 becomes ON.
When PGOOD of IC1930 becomes low (V+1R8_HHH or V+3R3_HHH drift from the setting value), Q1999 becomes
ON.
When V+6_DDD becomes lower than 3.8V, Q1999 becomes ON.
E
[How to Enter Release Mode]
During Standby mode, simultaneously press and hold the "?" and "MULTI-ZONE ON/OFF" keys
for 5 seconds.
www
F
64
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http://www.xiaoyu163.com
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Detection Method
Detect when XVDDERR
port becomes "L" (*1).
(IC8001 70pin)
Q1999
RN4903
D1997
1SS352
Q1999
D1998
RN4903
DAP202U
GNDD
V+6_DDD
x ao
y
. i
2
http://www.xiaoyu163.com
3
8
Status of Equipment
Shuts down Blinks PQLS LED
V+5_DDD
Q Q
3 6 7 1 3
D1995
UDZS6R8(B)
u163
.
SC-37
3
4
2 9 9 4 2 8
Warning Indication Remarks
V+13_UN
1 5 0 5 8 2 9 9 4
m
co
4
9 9
2 8 9 9