Fostex VM88, Service Manual

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VM88 VM88
42 3
PLL, DIGITAL, MAIN, VM88
U925
TC
9246
F
L7
22
uH
C2
7
220
/1
0
C1
3
0.
0
1
C1
4
0.
0
1
P
GND
D+
5
PGND
R
978
100
C3
4
0.
4
7
C1
5
0.
0
1
R
970
1K
R968
2
2
K
R
976
4.
7K
C3
5
15
P
C1
6
0.
0
1
R
974
330
R
975
750
1 2
3
U917
A
74
VH
C
8
6
4 5
6
U917
B
74
VH
C
8
6
D+
5
R
979
100
3
14
4
13
5
12
6
11 15
7
10
2 9 1
U919
A
74
VH
C
161
D+
5
1 2
3
U920
A
74
VH
C
0
0
4 5
6
U920
B
7
4V
H
C
00
9
10
8
U920
C
74
VH
C
0
0
S
4
D
2
CK
3
R
1
Q
5
Q
6
U923
A
74
VH
C
7
4
S
10
D
12
CK
11
R
13
Q
9
Q
8
U923
B
74
VH
C
7
4
S
10
D
12
CK
11
R
13
Q
9
Q
8
U924
B
74
VH
C
7
4
S
4
D
2
CK
3
R
1
Q
5
Q
6
U924
A
74
VH
C
7
4
S
4
D
2
CK
3
R
1
Q
5
Q
6
U922
A
74
VH
C
7
4
S
10
D
12
CK
11
R
13
Q
9
Q
8
U922
B
74
VH
C
7
4
C3
1
100
P
D+
5
DGND
DGND
D+
5
D+
5
2
3
1
U928 DTA
114
E
K
2
1
3
U929 DTC
114
E
K
R
984
10
K
R
985
10
K
D+
5
DGND
D+
5
D+
5
R
980
100
D+
5
R
981
2.
2K
C3
2
100
P
DGND
R
982
100
14
7
D+
5
DGND
14
7
14
7
14
7
14
7
16
8
C1
7
0.
0
1
C1
8
0.
0
1
C1
9
0.
0
1
C2
0
0.
0
1
C2
1
0.
0
1
C2
2
0.
0
1
S
4
D
2
CK
3
R
1
Q
5
Q
6
U921
A
74
VH
C
7
4
D+
5
D+
5
C3
3
100
P
DGND
DGND
14
7
C2
3
0.
0
1
LO
C
K
2
R971
1K
R
983
10k
D908 1S
S355
R
973
100
R972
100
12 13
11
U920
D
74
VH
C
0
0
D+
5
S
10
D
12
CK
11
R
13
Q
9
Q
8
U
921
B
74
H
C
74
L3 EM
I
D+
5
D+
5
L4 EM
I
X
902
C2
8
22
P
C2
9
22
P
DGND
DGND
R
986
1
M
3
4
U
927B
1
2
U
927
A
L5
L6
DGND
16
8
R969
NON
C2
4
0.
0
1
C2
5
0.
0
1
14
7
5
6
9
8
11
10
13
12
L9
8
820u
H
C3
6
0.
1
DGND
D+
5
DGND
MCK
MCK
[DIF]
FS512
FS512
MCK
LRCK
LRCK
DATA_IN
DATA_IN
U927C
74HC04
U927D 74HC04
U927E
74HC04
U927F
74HC04
FCONT2
/PLL1_CONT /PLL2_CONT
PD1 PD2
FCONT1
FCONT2 /PLL1_CONT /PLL2_CONT PD1 PD2 FCONT1
REF PD VDDA AMPI AMPO VSSA XI XO
VDD
LOCK
S2 S1
M2 M1
CKO
VSS
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
22.5792MHz
74VHCU04
74VHCU04
EMI
EXT//INT
EXT//INT
1A 1B 2A 2B 3A 3B 4A 4B A/B G
1Y 2Y 3Y 4Y
2 3 5 6
11 10 14 13
1
15
4 7 9 12
U926A
74VHC157
EMI
U917E
VCC GND
74VHC86
U919B
VCC GND
74VHC161
U920E
VCC GND
74VHC00
U921C
VCC GND
74VHC74
U922C
VCC GND
74VHC74
U923C
VCC GND
74VHC74
U924C
VCC GND
74VHC74
U926B
VCC GND
74VHC157
U927G
VCC GND
74VHCU04
2. MAIN_D, CPU
1. MAIN_D, ROOT
3. MAIN_D, DSP_ROOT 7. MAIN_D, GA_DIF
4. MAIN_D, DSP1 2 5. MAIN_D, DSP3 6. MAIN_D, DSP SEL 8. MAIN_D, PLL
SPDIF//ADAT
LOCK2
SPDIF//ADAT
A B C D ENP ENT CK LOAD CLR
QA QB QC QD
RCO
Parts marked with this sign are safety critical components. They must always be replaced with identical
components. Refer to the Fostex Parts List and ensure exact replacement.
CAUTION
TABLE OF CONTENTS
Owner's manual : 8288458000 (for export & domestic model)
Service mode, exploded view, PCB assembly, parts list and circuit diagrams are given in this manual
to assist the service technician in maintaining the Model VM88.
NOTES
The following accessories are supplied with VM88 as the standard accessories. *
*
Following is the packing material for the Model VM88. *
Carton, inner, VM88 : 8228737000
Packing, side, L, VM88 : 8228465001
Packing, side, R, VM88 : 8228465002
1. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. CONTROLS, INDICATORS AND CONNECTORS . . . . . . . . . . . .
3. SERVICE MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. EXPLODED VIEW, PCB ASSEMBLY AND PARTS LIST . . . . . .
5. CIRCUIT AND BLOCK DIAGRAMS . . . . . . . . . . . . . . . . . . . . . .
4
6
7
10
23
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