Adjustment Procedure - Onkyo HTP-820 Service Manual

ADJUSTMENT PROCEDURE

SKW-820 : POWERED SUBWOOFER /
ADJUSTMENT OF IDLING CURRENT
1. Before adjustment of idling current, turn the trimming resistor R544 to counter clockwise.
2. Short test point P631 for Amplifier is under active mode.
3. Connect the DC voltmeter to test point P531.
4. After turn POWER to ON, adjust the trimming resistor R544 so that the reading of voltmeter
becomes 0.25 mV.
<Note> No speaker load and No input signal.
5. Confirm the voltage of above point after five minutes.
6. When less than 4.40 mV
When 4.41 mV to 5.50 mV : Not necessary to adjust.
When more than 5.51 mV
Trimming resistor
R544
R542
R543
E
C
B
C528
C527
R510
Q504
R504
D651
: Readjust the trimming resistor above so that the voltage becomes 4.5 mV to 5.0 mV.
: Readjust the trimming resistor above so that the voltage becomes 5.0 mV to 5.5 mV.
Test point
P531
Q541
C E
B
B C E +Vcc
17
Q515
J313
22
J331
J308
R531
R533
12
J322
C519
J372
P531
-Vee
J323
R508
C520
C526
J319
E J320
+Vcc
C
B
R512
7
J312
J321
R516
R515
C504
R507
R527
P502A
R509
C505
Q502
R522
Q501
R521
Q302
1
J385
8
+15V
Amplifier PC board "NAAF-8275"
Q952
Q516
B C E
B C E J345
15
25
-Vee 17
J344
C906
R954
D952
C954
D901
C903
J355
J354
C904
AC_IN
7
J342
17
J329
17
J330
7
P901A
J343
J337
J353
12
J338
12
J352
7
J339
led_socket
R971
-15V
J334
7
Q601
+15V
1
C905
Q301
1
J332
8
8
Q951
B C E
R951
R952
R953
D951
D902
C953
JL601
JL601A
D903
15
R619
R617
J358
P632A
Test point
R621
P631
R603
R609
R610
Q602
P633
NCAF-8275
25138275B
1
HTP-820