Service manual

46
VSX-918V-K
1
2 3 4
A
B
C
D
E
F
1
2 3 4
D713
1SS133
Q702
2SA2005(E)
Q701
2SC5511(E)
D+5V
Voltage supply
to POWER AMP IC
(V neck-)
Voltage supply
to POWER AMP IC
(V neck+)
R697
10k
R698
33k
R713
1k
R807
10k
D801
S1WB(A)60SD
D807
D806
MTZJ6.2B
Q807(2/2)
Q807(1/2)
Q808(1/2)
D+5.6V
Q808(2/2)
Q698
Voltage supply
to +12 V
REGULATOR IC
Voltage supply
to -12 V
REGULATOR IC
C806
1/50
C801
2200
/25
C802
2200
/25
R806
10k
R808
1k
IC9001
(U-P)
XPROTECT
4. XPROTECT Detection Circuit Diagram
When below 6 kind of voltage supply become to
be short circuit to GND, XPROTECT circuit work
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
POWER PACK ASSY
MAIN ASSY
89
C
A