Yamaha Mg12.4 Service Manual
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![Page 8
8 MG12/4
MG16/4
q[GAIN] Control
w[PEAK] Indicator
e[
80 ] Switch (High Pass Filter)
rEqualizer ([HIGH], [MID], [LOW])
t[AUX1] and [AUX2] Controls
y[PRE] Switch
u[PAN] Control (MG16/4: CHs 1 to 8. MG12/
4: CHs 1 to 4)
[PAN/BAL] Control (MG16/4: CHs 9/10 and
11/12. MG12/4: CHs 5/6 and 7/8)
[BAL] Control (MG16/4: CHs 13/14 and 15/
16. MG12/4: CHs 9/10 and 11/12)
i[
] ST Switch
o[PFL] (Pre-Fader Listen) Switch
!0[GROUP] Switch
!1Channel Fader
PANEL LAYOUT
Note: Within this manual, all panel...](http://img.usermanuals.tech/thumb/83/104158/w64_d_1519721431-yamaha-mg12-4-service-manual_d-7.png "Page 8
8 MG12/4
MG16/4
q[GAIN] Control
w[PEAK] Indicator
e[
80 ] Switch (High Pass Filter)
rEqualizer ([HIGH], [MID], [LOW])
t[AUX1] and [AUX2] Controls
y[PRE] Switch
u[PAN] Control (MG16/4: CHs 1 to 8. MG12/
4: CHs 1 to 4)
[PAN/BAL] Control (MG16/4: CHs 9/10 and
11/12. MG12/4: CHs 5/6 and 7/8)
[BAL] Control (MG16/4: CHs 13/14 and 15/
16. MG12/4: CHs 9/10 and 11/12)
i[
] ST Switch
o[PFL] (Pre-Fader Listen) Switch
!0[GROUP] Switch
!1Channel Fader
PANEL LAYOUT
Note: Within this manual, all panel...")
![Page 9
9 MG12/4
MG16/4
q[ST] Master Fader
w[GROUP 1-2] Fader
e[ TO ST ] Switch
rMaster SEND ([AUX1] and [AUX2] Controls)
tRETURN ([AUX1], [AUX2], and [ST] Controls)
y[2TR IN] Control
u[PHANTOM +48V] Switch
iLevel-Meter Signal Switches
(ST-GROUP Toggle Switch and 2TR IN Switch)
o[C-R/PHONES] Control
!0Level Meter
!1[POWER] Indicator
!2[PHONES] jack
y
u!2
!1
!0
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9 MG12/4
MG16/4
q[ST] Master Fader
w[GROUP 1-2] Fader
e[ TO ST ] Switch
rMaster SEND ([AUX1] and [AUX2] Controls)
tRETURN ([AUX1], [AUX2], and [ST] Controls)
y[2TR IN] Control
u[PHANTOM +48V] Switch
iLevel-Meter Signal Switches
(ST-GROUP Toggle Switch and 2TR IN Switch)
o[C-R/PHONES] Control
!0Level Meter
!1[POWER] Indicator
!2[PHONES] jack
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!1
!0
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![Page 10
10 MG12/4
MG16/4
qChannel Input jacks
[MIC] jacks (MG16/4: CHs 1 to 8, 9/10, 11/12.
MG12/4: CHs 1 to 4, 5/6, 7/8)
[LINE] jacks (MG16/4: CHs 1 to 8. MG12/4: CHs
1 to 4)
w[INSERT I/O] Jacks
(MG16/4: CHs 1 to 8. MG12/4: CHs 1 to 4)
eChannel Input jacks
Phone type (MG16/4: CHs 9/10 to 15/16. MG12/4:
CHs 5/6 to 11/12)
RCA pin type (MG16/4: CHs 13/14, 15/16. MG12/
4: CHs 9/10, 11/12)
r[GROUP OUT] (1, 2) Jacks
t[ST OUT] (L, R) Jacks
y[C-R OUT] Jacks
u[SEND] Jacks
i[RETURN L] (MONO), [RETURN R] Jacks
o[REC OUT]...](http://img.usermanuals.tech/thumb/83/104158/w64_d_1519721431-yamaha-mg12-4-service-manual_d-9.png "Page 10
10 MG12/4
MG16/4
qChannel Input jacks
[MIC] jacks (MG16/4: CHs 1 to 8, 9/10, 11/12.
MG12/4: CHs 1 to 4, 5/6, 7/8)
[LINE] jacks (MG16/4: CHs 1 to 8. MG12/4: CHs
1 to 4)
w[INSERT I/O] Jacks
(MG16/4: CHs 1 to 8. MG12/4: CHs 1 to 4)
eChannel Input jacks
Phone type (MG16/4: CHs 9/10 to 15/16. MG12/4:
CHs 5/6 to 11/12)
RCA pin type (MG16/4: CHs 13/14, 15/16. MG12/
4: CHs 9/10, 11/12)
r[GROUP OUT] (1, 2) Jacks
t[ST OUT] (L, R) Jacks
y[C-R OUT] Jacks
u[SEND] Jacks
i[RETURN L] (MONO), [RETURN R] Jacks
o[REC OUT]...")
![Page 16
16 MG12/4
MG16/4
2. Bottom Cover
(Time required : About 3 min.)
2-1. Remove the rack mount angle L and R.
(See procedure 1)
2-2. Remove the eight (8) screws marked [500]. The bottom
cover can then be removed. (Fig. 1)
1. Rack Mount Angle
(Time required : About 1 min.)
1-1.Remove the two (2) screws marked [510A]. The rack
mount angle L can then be removed. (Fig. 1)
1-2. Remove the two (2) screws marked [510B]. The rack
mount angle R can then be removed. (Fig. 1)
Rack mount angle R Rack mount angle L
(Fig....](http://img.usermanuals.tech/thumb/83/104158/w64_d_1519721431-yamaha-mg12-4-service-manual_d-15.png "Page 16
16 MG12/4
MG16/4
2. Bottom Cover
(Time required : About 3 min.)
2-1. Remove the rack mount angle L and R.
(See procedure 1)
2-2. Remove the eight (8) screws marked [500]. The bottom
cover can then be removed. (Fig. 1)
1. Rack Mount Angle
(Time required : About 1 min.)
1-1.Remove the two (2) screws marked [510A]. The rack
mount angle L can then be removed. (Fig. 1)
1-2. Remove the two (2) screws marked [510B]. The rack
mount angle R can then be removed. (Fig. 1)
Rack mount angle R Rack mount angle L
(Fig....")
11 MG12/4
MG16/4
Connector Polarities
* These jacks will also accept connection to monaural phone plugs. If you use monaural plugs, the connection will be unbalanced.
MIC INPUT, ST OUTPin 1: Ground
Pin 2: Hot (+)
Pin 3: Cold (–)
LINE INPUT (monaural channels),
GROUP OUT, ST OUT, C-R OUT
AUX1, AUX2 *Tip: Hot (+)
Ring: Cold (–)
Sleeve: Ground
INSERT I/OTip: Output
Ring: Input
Sleeve: Ground
PHONESTip: L
Ring: R
Sleeve: Ground
RETURN
LINE INPUT (stereo channels)Tip: Hot
Sleeve: Ground
INPUT OUTPUT
Ring
Sleeve Tip
Sleeve Tip
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LINE INPUT
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GROUP OUT
z ST OUT
z C-R OUT
AUX 1
z AUX 2
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INSERT I/O
½¿Ó Output
æï¬ Input
µæ”Ò¬å¢ïÅ
PHONES
½¿Ó L
æï¬ R
µæ”Ò¬å¢ïÅ
RETURN
LINE INPUT ¢µÂ覽ßïÉç£
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INPUT OUTPUT
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12 MG12/4 MG16/4 Shrink tube (Seven places)¢ ä ) V½á”ÒU t£ Redž§Brown½ß Black«é WA595400 WE735800 MG12/4 CIRCUIT BOARD LAYOUT & WIRING PS Power switch and AC connector wiring MAIN JACK 1/2 JACK 1/2JACK 2/2 ¢.( âÇ¿Äè ž¢ÄÍA ¢ $£ ¢ ?oµ ¿½q$¯É«»wA ¢£
13 MG12/4 MG16/4 WC703300 (7 places) CN571 (JACK 1/2 circuit board) --- CN501 (MAIN circuit board) CN771 (JACK 1/2 circuit board) --- CN701 (MAIN circuit board) CN971 (JACK 1/2 circuit board) --- CN901 (MAIN circuit board) CNA71 (JACK 1/2 circuit board) --- CNA01 (MAIN circuit board) CND71 (JACK 1/2 circuit board) --- CND01 (MAIN circuit board) CNE71 (JACK 1/2 circuit board) --- CNE01 (MAIN circuit board) CNG71 (JACK 1/2 circuit board) --- CNG01 (MAIN circuit board)MAIN circuit board WE521500MAIN circuit board WE521500JACK 2/2 circuit board WE675700 CNH02 JACK 1/2 circuit board WE675700WD361600 CNH01 CNF01 MAIN circuit board and JACK circuit board wiring Wiring to PS circuit board WE735800 WD361600 CN02PS circuit board WE522200 CN01 ¢.*/³”Äq+$,³”ÄwA ¢£
14 MG12/4 MG16/4 Shrink tube (Seven places)¢ ä ) V½á”ÒU t£ Redž§Brown½ß Black«é WA595400 WE735800 MG16/4 CIRCUIT BOARD LAYOUT & WIRING PS MAIN Power switch and AC connector wiring JACK 1/2 JACK 2/2JACK 1/2 ¢.( âÇ¿Äè ž¢ÄÍA ¢ $£ ¢ ?oµ ¿½q$¯É«»wA ¢£
15 MG12/4 MG16/4 WE735800 WD361600 CN02PS circuit board WE522200 CN01 WC703300 (9 places) CN171 (JACK 1/2 circuit board) --- CN101 (MAIN circuit board) CN371 (JACK 1/2 circuit board) --- CN301 (MAIN circuit board) CN571 (JACK 1/2 circuit board) --- CN501 (MAIN circuit board) CN771 (JACK 1/2 circuit board) --- CN701 (MAIN circuit board) CN971 (JACK 1/2 circuit board) --- CN901 (MAIN circuit board) CNA71 (JACK 1/2 circuit board) --- CNA01 (MAIN circuit board) CND71 (JACK 1/2 circuit board) --- CND01 (MAIN circuit board) CNE71 (JACK 1/2 circuit board) --- CNE01 (MAIN circuit board) CNG71 (JACK 1/2 circuit board) --- CNG01 (MAIN circuit board)MAIN circuit board WE521600MAIN circuit board WE521600JACK 2/2 circuit board WE573100 CNH02 JACK 1/2 circuit board WE573100WD361600 CNH01 CNF01 MAIN circuit board and JACK circuit board wiring Wiring to PS circuit board¢.*/³”Äq+$,³”ÄwA ¢£
16 MG12/4 MG16/4 2. Bottom Cover (Time required : About 3 min.) 2-1. Remove the rack mount angle L and R. (See procedure 1) 2-2. Remove the eight (8) screws marked [500]. The bottom cover can then be removed. (Fig. 1) 1. Rack Mount Angle (Time required : About 1 min.) 1-1.Remove the two (2) screws marked [510A]. The rack mount angle L can then be removed. (Fig. 1) 1-2. Remove the two (2) screws marked [510B]. The rack mount angle R can then be removed. (Fig. 1) Rack mount angle R Rack mount angle L (Fig. 1) [430]: Bind Head Tapping Screw-S 3.0 x 6 MFZN2B3 (WE877800) [500]: Bind Head Tapping Screw-S 3.0 x 6 MFZN2B3 (WE877800) [510]: Bind Head Screw 4.0 x 8 MFZN2B3 (WE969000) MG12/4 DISASSEMBLY PROCEDURE¢ ür q£ [510A] [510A][500] [500][510B] [510B] [500] [500] [500] [500] [430A] [430C] [500] [500]Bottom cover
17 MG12/4 MG16/4 3. PS Circuit Board (Time required : About 4 min.) 3-1. Remove the rack mount angle L and R. (See procedure 1) 3-2. Remove the bottom cover. (See procedure 2) 3-3.Remove the two (2) screws marked [480]. The PS circuit board and heat sink can then be removed. (Fig. 2) * Replacing any part on the PS circuit board requires removal of the heat sink as well. Use the following procedure to remove the heat sink. 3-4. Remove the two (2) screws marked [A] fixing IC01 and IC05. (Photo 1) 3-5. Remove the three (3) screws marked [B]. (Photo 1) 3-6. Remove the solder IC02, IC03 and Q01. The heat sink can then be removed from the PS circuit board. (Photo 1) 4. Side Cover (Time required : About 5 minutes each.) 4-1. Remove the rack mount angle L and R. (See procedure 1) 4-2. Remove the bottom cover. (See procedure 2) 4-3. Side Cover L : 4-3-1.Remove the screw marked [430A], two (2) screws marked [430B], three (3) screws marked [440A] and two (2) screws marked [450A]. The side cover L can then be removed. (Fig. 2) 4-4. Side Cover R : 4-4-1. Remove the PS circuit board. (See procedure 3) 4-4-2.Remove the screw marked [430C], two (2) screws marked [430D], three (3) screws marked [440B] and two (2) screws marked [450B]. The side cover R can then be removed. (Fig. 2) 5. MAIN Circuit Board, Jack 1/2, 2/2 Circuit Board (Time required : About 15 min.) 5-1. Remove the rack mount angle L and R. (See procedure 1) 5-2. Remove the bottom cover. (See procedure 2) 5-3. Remove the PS circuit board. (See procedure 3) 5-4. Remove the side cover L and R. (See procedure 4) 5-5. Pull out the ten (10) fader knobs. (Fig. 2) 5-6. Remove the two (2) screws marked [450C]. (Fig. 2) 5-7.Remove the eighteen (18) screws marked [460] and twenty-six (26) hexagonal nuts. The MAIN and JACK 1/2, 2/2 circuit boards can then be removed. (Fig. 2) Disconnect the seven (7) connectors and separate the MAIN circuit board and the JACK 1/2 circuit board. * The knobs, buttons and supporting fixtures on the MAIN circuit board are not components of the circuit board. When replacing the MAIN circuit board, be sure to remove these parts according to the following procedure. 14
18 MG12/4 MG16/4 Side cover RSide cover L [440B] [440B] [440B] [480] [480][440A] [440A] [440A] [450B] [450B][450A] [450A] [450C] [450C] [430B] [430B] [430D] [430D] [460] [460]Fader knobs Hexagonal nuts Hexagonal nuts [430C][430A] PS PS (Fig. 2) [430]: Bind Head Tapping Screw-S 3.0 x 6 MFZN2B3 (WE877800) [440]: Bind Head Tapping Screw-S 3.0 x 6 MFZN2W3 (WE877900) [450]: Hex. Socket Set Screw-S 3.0 x 6 MFZN2B3 (WF419300) [460]: Bonding Tapping Screw-B 3.0 x 10 MFZN2B3 (WE878000) [480]: Bind Head Tapping Screw-B 3.0 x 8 MFZN2W3 (WE774300) 5-8. Remove the hexagonal nut. The JACK 2/2 circuit board can then be removed from the MIX1 support. (Fig. 3) 5-9.Pull out the sixty-one (61) volume knobs from the MAIN circuit board. (Fig. 2) 5-10. Remove the eight (8) push ON buttons, eight (8) sleeve ON buttons, nine (9) push PFL buttons and twenty-five (25) push HPF buttons from the MAIN circuit board. (Fig. 3) 5-11. Remove the three (3) screws marked [420]. The MIX2 support can then be removed from the MAIN circuit board. (Fig. 3) 5-12. Twist the six (6) hooks of the MIX1 support (upper) to become straight, and the support can be removed from the MAIN circuit board. (Fig. 3) Volume knobs MAIN MAIN JACK 2/2 JACK 1/2JACK 1/2
19 MG12/4 MG16/4 (Photo 1) [420]: Bind Head Tapping Screw-S 3.0 x 6 MFZN2W3 (WE877900) (Fig. 3) Push HPF buttons Hooks Push HPF buttons Push HPF buttons Push ON buttons Push PFL buttons Push PFL buttons Sleeve ON buttons [420] [420] [420]Hexagonal nuts MIX1 support (upper) MIX1 support (lower) MIX2 support Meter cover Meter reflector [B] IC01 IC02 IC03IC05 Q01 [B] [A] [A] PS PS JACK 2/2 MAIN * The upper and lower MIX1 support each can then be removed in the same manner. 5-13. Detach the meter cover from the meter reflector. (Fig. 3) [A]: Bind Head Tapping Screw-B 3.0 x 8 MFZN2W3 (WE774300) [B]: Bind Head Tapping Screw-B 3.0 x 8 MFZN2W3 (WE774300)
20 MG12/4 MG16/4 Hexagonal nut and flat washer ¢á¯Æ¿