Pioneer VSX-418-K Service Manual page 24

1
4. XPROTECT Detection Circuit Diagram
When below 6 kind of voltage supply become to
be short circuit to GND, XPROTECT circuit work
A
and U-P input port voltage change from +5 V to 0 V.
The U-P detect this condition as ERROR.
• Voltage supply to POWER AMP IC (V neck+)
• Voltage supply to POWER AMP IC (V neck-)
• Voltage supply to +12 V REGULATOR IC
• Voltage supply to -12 V REGULATOR IC
B
A MAIN ASSY
XPROTECT
C
D
E
F
24
1
2
IC9001
(U-P)
89
2
3
Voltage supply 2SC5511(E)
to POWER AMP IC
(V neck+)
R713
D713
1k
1SS133
D+5V
C
R697
10k
Q698
R698
33k
Voltage supply
to POWER AMP IC
(V neck-)
2SA2005(E)
Voltage supply
to +12 V
REGULATOR IC
D+5.6V
D807
Q807(2/2)
R807
R808
10k
1k
Q808(2/2)
R806
C806
10k
1/50
Voltage supply
to -12 V
REGULATOR IC
VSX-418-K
3
4
Q701
POWER PACK ASSY
Q702
Q807(1/2) C801
2200 D801
/25 S1WB(A)60SD
Q808(1/2)
C802
2200
/25
D806
MTZJ6.2B
4