Power Amp; Power Supply - Yamaha KMA-1080 Service Manual

A B C
KMA-1080/KMA-980
MAIN 1/2
1

POWER AMP

2
72.3
71.1
3
L
CB401
0
0
4
5
72.3
71.1
6
0
0
7
8
9
10
36
D E F
Page 32 H7
to FUNCTION (1)_W2
Temperature sensor for heatsink Temperature sensor for power transformer
IC401 IC402
5.1 5.1 1.0
1.0
0 0
R441
KMA-1080 3.3K
KMA-980 1.8K
4.6
5.7
4.6
4.6
4.6
0 0
5.7
0
0
0
-5.5
0
0
-4.5
-4.5
0 -5.5
-5.0
-4.5
R442
KMA-1080 3.3K
KMA-980 1.8K
4.6
5.6
5.2
4.6
4.6
0 0
5.7
0
0
0
-5.5
0
0
-4.5
-4.5
0
-5.5
-5.1
-4.5
IC401, 402: LM61CIZ
Temperature sensor
G H I
0
0
0
0
0
5.1
0
0
0
0
0
6
CH 2
0
0
17.3
17.3
0
Point y
CH 1 : Emitter of Q433
CH 2 : Collector of Q431
↑ ↑
Power cable on Power cable off
J K
KMA-1080
W404
W402
R
SPEAKERS
W403
A/B
L
W401
to POWER TRANSFORMER
CB408
F402
4A 250V
KMA-1080
KMA-980 3.15A 250V
AC OUTLETS
W405
W406
CB409
Page 35 J2
to OPERATION (7)_CB562

POWER SUPPLY

POWER CABLE
AC IN
0
72.3
(53.6)
KMA-1080
-72.2
(-53.5) CB411
Page 35 K7
to OPERATION (1)_W201
0
KMA-980
to POWER TRANSFORMER
C457, 458
12000/85
KMA-1080
KMA-980 12000/71
17.9
0 0
AC28.9
6
CH 1
CB412
-16.7
AC9.0
9.7
4.7
4.7
17.3
0
0
Page 37 A4
to MAIN (2)_W551
↑
Power cable on
L M N
KMA-980
R
SPEAKERS
L
* All voltages are measured with a 10MΩ/V DC electronic volt meter.
* Components having special characteristics are marked Z and must be replaced
with parts having specifications equal to those originally installed.
* Schematic diagram is subject to change without notice.
O