Idle Current Adjustment - Pioneer VSX-1127-K Service Manual

1

8.4 IDLE CURRENT ADJUSTMENT

A
When any component parts which are within the red square on the following circuit diagram are replaced, the idle current
adjustment of that channel is required. (Idle current adjustment for another channel is not required.)
However, when any capacitors are replaced, the adjustment is not required.
(The following circuit diagram is for SL channel, but another channel also has same circuit diagram and same adjustment is
required)
B
R533
2R2
C472
R600
R601
1K2
1K5
22/50
C
Measurement
Channel
TP404 pin 1 (+)
FL
TP404 pin 3 (–)
TP402 pin 1 (+)
FR
TP402 pin 3 (–)
TP403 pin 1 (+)
C
TP403 pin 3 (–)
TP401 pin 1 (+)
SL
TP401 pin 3 (–)
TP405 pin 1 (+)
SR
D TP405 pin 3 (–)
TP406 pin 1 (+)
SBL
TP406 pin 3 (–)
TP407 pin 1 (+)
SBR
TP407 pin 3 (–)
• Adjustment points and measurement points.... see fig.1.
B
AMP7 ASSY
SL_VR401 FL_VR404
E
VR404 FL ADJ
SL ADJ
VR401
SL ADJ
TP401
F
SL_TP401
54
1
2
R574
1K2
Q449
KTA1024Y
C470
R535
2R2
C469 220P-500V
82P-J
R602
Q455 Q456
33K
KSA992F KSA992F
R607
3K3(1)
Q460
KTC3206Y
C477 R613 R715
150 270
2N2-K
C548
-
Adjustment
Points Points
VR404
VR402
VR403
VR401
VR405
VR406
VR407
C_VR403
C ADJ
TP403
C ADJ
VR403
FL ADJ
TP404
C(+)
J583
FL_TP404 C_TP403
2
3
C468
47/50(6.3*11)
R588
100(1)
Q457
KTC3964
VR405
1K(B)-V
R612
100(1)
C483 -
1 Turn on the power.
2 Perform aging for one minute.
3 Connect a digital voltmeter to the measurement point.
4 Turn the adjustment VR so that the voltage becomes
in 2.0 mV ± 0.2 mV.
(Condition : No signal and no load)
SR_VR405 FR_VR402
FR ADJ
VR402
SR ADJ
VR405
SR ADJ
TP405
SR(+)
SR_TP405 FR_TP402
Fig.1
VSX-1127-K
3
4
TP405
1 2 3
Q452
R584 270K
2SD2390
D426 R590
270K
1SS133T
R596
10K
Q458
2SB1560
Procedure
SBL_VR406 SBR_VR407
SBR ADJ
VR407
SBL ADJ
FR ADJ
VR406
TP402
SBL ADJ
TP406
SBL_TP406 SBR_TP407
4
Q451
2N5401S
SIDE A
SBR ADJ
TP407