Yamaha RX-Z11 Service Manual page 22

RX-Z11/DSP-Z11
2. Removal of MAIN R P.C.B.
a. Remove 6 screws (1), 2 screws (2) and then remove
the top cover. (Fig. 6)
b. Remove 4 screws (B) and then remove the panel side
R. (Fig. 6)
c. Remove 4 screws (C), 4 screws (D) and then remove
the frame top L. (Fig. 6)
d. Remove 2 push rivets (E) and then remove the sup-
port wire. (Fig. 6)
e. Remove 2 screws (F) and 2 screws (G). (Fig. 6)
f. Remove CB26, CB911, CB913, CB927. (Fig. 7)
g. Remove 10 screws (H) and then remove ST912-920
and ST922. (Fig. 7, 8)
h. Remove the main R unit. (Fig. 6)
i. Remove 4 screws (I). (Fig. 8)
j. Remove CB914-919. (Fig. 7)
k. Remove solder from all the power transistor leads.
(Fig. 8)
l. Remove the MAIN R P.C.B.. (Fig. 8)
Top cover
3
Panel side L
1
1
3
4
5
4
7 7
Support wire
8
Frame top L
9
4
Main L Unit
Main L
9
22
1 2
B
C D
E
F G
H
I
2
D
1
C
C
Frame top R
E
Support wire
E
F
G
C
G
Main R Unit
Main R
Panel side R
B
Fig. 6
* Caution when replacing power transistors
• When replacing power transistors, be sure to replace
2 of them for each channel as a pair (2SA2121/
2SC5949) at the same time.
• When installing power transistors, first securely fix
them to the heat sink by screwing, next install the
P.C.B. and then solder the power transistor leads.
• When soldering, if the power transistors become
loose from the heat sink, once unsolder and se-
curely fix them, and then solder them again. (Fig. 8)
ST912 : YELLOW
H
CB916
CB918
B
CB915
A
C
A
A : 2SA2121
C : 2SC5949
ST915 : BLACK
ST917 : ORANGE CB911
ST913 : BLUE ST922 : BLACK MAIN R P.C.B.
ST918 : WHITE
H
CB913
CB927
ST916 : BLUE ST920 : VIOLET
ST914 : RED ST919 : RED
Fig. 7
Heat sink
OK
Power transistor
CB917
CB914
CB919
C
A I
C
A
C
A
C
A
C
MAIN R P.C.B.
I
Fig. 8
CB26
Heat sink
NG
Power transistor