Main PCB 1/6

+ 5 V

Q 5

R H 5 V A 4 3

R 1 0 4

R S T L

1 6 A , 1 6 B , 3 4 D , 4 7 B , 5 7 E

# 8

1 . 5 K

T 7 D 9 8

V C C

O U T

4 4

6 4

R S T L 1 4 A

R S T

R T C C O N

G N D

6 1

+ 5 B

C 8 7

C 6 1

R V D D

1 4 3

6 2

+ 2 5 V + 5 V

C C 1 0 4

E X T L

R E X T

1 4 1

6 3

P A N E L

X T L

R X T

C 6 2

R 8 2

1 0 0

7 0

C C 1 0 4

2 5 C R A S

X T 3

G N D

R 1 0 5 1 0 0

R A S 0

7 5

2 0 2

C R X D

C - 0 0 1 R

2 5 C C A S

C A S

C R X D

1 2 4

1 9 9

C K S

G N D

2 7 B R M R D

R M R D

C K S

R 4 3 2 7 0

1 2 3

1 9 6

T X D

1 6 B P C L K

R M W E

T X D

C 7 1

C 7 0

1 2 2

1 9 7

R X D

X T 1

C C 1 0 P

C C 1 5 P

1 5 P 1 5 P

2 7 B R O M C

R O M C

R X D

1 6 B S D O U T

C S T 1 6 M X W

1 6 6

1 9 8

C T S

R 4 4

I O R D

C T S

P B U S

5 6 B

1 6 7

1 6 B S D I N

I O W E

R 1 3 8 4 7 0

G N D

8 4

M M 1

1 7 7

8 5

M M 2

G N D

1 2 B P C L K

P C L K

M M 2

1 2 B S D O U T

1 7 6

8 6

M M 3

S D O U T

M M 3

1 7 5

8 7

M M 4

P 1 3 1 / 2

C 1 0 9

C 4 0

C 4 1

C 3 9

1 2 B S D I N

S D I N

M M 4

M B U S 2 3 C

C C 1 0 4

C C 1 0 1

R 7 8

+ 5 B

6 7

4 5

L 5 V

C K 3 2 O N

T S T A

6 6

4 6

C K 3 2

T S T B

G N D

R 7 7 1 0 0

1 2 5

I O R Q

R 1 0 3

1 0 K

6 8

1 2 6

M R E Q

L 5 V

B A K C L K

M R E Q

1 4 A R S T L

7 3

1 4 0

C K 1 6

B A E N B

C K 1 6

+ 5 B

7 4

1 4 4

R 1 0 2

C 6 3

B A V D D

C K 8 M

+ 5 V

6 5

1 4 5

R D

C C 1 0 2 B

G N D

B A K S E L

R D

# 8

2 5 C B A R M R D

7 2

1 4 6

C 6 4

B A R M R D

R B U S

3 4 D

T 7 D 9 8

2 5 C B A R M W E

7 1

1 6 8

C C 1 0 4

B A R M W E

N M I

R 7 2

G N D

1 6 9

R 2 2

N T

5 7

1 7 0

R 7 4

1 0 K

1 7

1 6

2 0 0

A D M D

4 2 F A D L C

L N C R ( C O M P )

B S A K

3 3 A L I G T

G N D

8 3

1 7 1

M I O 0 ( P W M ) A D P D M D

4 6 E V O L 1

R 7 1

1 0 k

1 8

1 4

A A M D

S O L ( O D )

B S R Q

4 1 F D A S N D

8 2

1 7 2

M I O 1 ( P W M ) A A P D M D

4 1 E

E A T

R 7 3 1 0 k

1 9

1 2

R 7 0

2 0 0

D M T

P W O N

WA I T

4 3 D D A R E C

1 8 7

1 7 3

M I O 2 ( P W M ) D P D M D T

3 5 F , 4 2 B C M L H

R 1 2 8 1 0 k

2 0

1 1 R 2 4

3 0 0

D M K

C M L

R F S H

1 8 8

1 7 4

M I O 3

D P D M C K

4 1 E R D P S

R 1 2 9 1 0 k

2 1

R 6 9

3 0 0

A M K

D P S

M 1

1 8 9

M I O 4

A P D M C K

4 2 E

P L S

R 7 5

1 0 k

2 2

A M T

P L S

L 5 V

1 9 1

1 3 6

A 0

R 1 3 7

M I O 5

A P D M D T

4 3 A T E L L

2 3

C 3

T E L

A 0

C 5 8

C 5 7

C 5 9

4 3 B T A D H

1 9 2

1 3 7

A 1

M I O 1 1

C 5

3 7 E H O O K

2 4

C 4

H O O K

A 1

C C 1 0 4

4 4 D T X S L

1 9 3

1 3 8

A 2

M I O 1 2

C 4

4 2 F

C I

2 5

C 5

C I

A 2

4 5 D H A F H

1 9 4

1 3 9

A 3

M I O 1 3

C 3

4 2 F T L O F

2 0 5

C 0

T L O F

A 3

+ 5 V

1 9 5

1 4 8

A 4

M V D D

C 2

L 5 V

C 1

S T D

A 4

3 9

1 4 9

A 5

G N D

C 8 3

C 1

4 5 E R N G O

C 2

R I N G

A 5

A 6

4 0

1 5 0

C C 1 0 4

C 0

4 6 E S P O N

2 0 8

1 3

A M U T

S P O N

A 6

G N D

1 8 4

1 5 1

A 7

M V S S

A M U T E

4 6 D R N G L

2 0 4

M U T

E 2 C S

A 7

2 0 3

1 5 2

A 8

M O N M D C K

M U T E

4 2 D

O T O

T B U S 4 8 A , 5 8 D

C T X D

A 8

1 5 3

A 9

R 1 3 0

1 0 3

2 0 7

A 9

4 1 F D A S T

L I G T ( P W M )

M E X T L

1 5 4

A 1 0

2 0 6

A 1 0

8 9

1 5 5

A 1 1

M T X L

R 1 2 7 1 M

3 2 F L A T C

8 0

P O 1

A 1 1

1 8 5

1 5 7

C 1 1 1

4 6 E V O L 3

S E O N ( O D )

R 1 1 9 2 0 0

3 3 C C L M P

P O 2

A 1 2

7 6

1 0 9

D A 0

3 7 C R I B N

1 8 6

1 5 8

S E N 2

D A 0

R 6 8

3 3 C C P WM

7 7

1 1 0

R 1 1 8

D A 1

X T 2

P 0 3 ( O D )

A 1 3

A B U S 2 6 B , 3 4 D

1 5 9

S E N 3

D A 1

4 7 0

2 0 0

D 1 4 . 4 M H z

A 1 4

7 8

1 1 1

D A 2

4 2 F T L O F 2

1 6 0

S E N 4

D A 2

7 9

1 1 2

R A 1

D A 3

A 1 5

G N D

3 7 B F S E N

2 6

1 6 1

S E N 5

D A 3

2 0 0

3 0

1 1 3

D A 4

R M 1

M A 1 6

3 7 B R S E N

C 8 2

C 5 4

2 7

1 6 2

S E N 6

D A 4

2 5 B E P C K

3 1

1 1 5

D A 5

C C 2 7 P

R M 2

M A 1 7

3 7 D C S E N

2 8

1 6 3

S E N 7

D A 5

2 3 F

S O L

R M 3

M A 1 8

G N D

3 2

1 1 6

D A 6

3 7 C R E A R

2 9

+ 5 V

E 5 V

S E N 8

D A 6

3 5 E P W O N

1 1 7

R A 2

D A 7

R M 4

1 7 8

D A 7

2 0 0

O D P I

1 1 8

D A 8

O 0

1 7 9

D A 8

O D P I

9 2

1 2 0

D A 9

G N D

R 1 0 1 *

O 1

3 2 E

S T 1

1 8 2

1 8 0

S T 1

D A 9

G N D

9 1

D A B U S

P I O 1

O D P I O 2

3 2 E

S T 2

2 6 B , 2 5 E

1 8 3

1 8 1

9 3

1 2 7

D 0

P I O 2

O D P I O 3

3 2 E

H D C

1 0 8

4 2

H D C

D 0 0

3 4 C S R A M

V O L 2 4 6 E

9 4

1 2 8

D 1

P I O 3 ( S R A M ) O D P I O 4

3 2 E

D I N

4 1

D I N

D 0 1

2 5 B E P D O

9 0

1 2 9

D 2

P I O 4 ( O D )

3 2 E D O U T

1 2 1

3 3

D O U T

D 0 2

4 5 A H R A D

1 3 0

D 3

P I O 5

F D C L K

6 9

3 4

D 0 3

O 6

1 3 1

D 4

P I

F D O U T

3 5

D 0 4

G N D

E 0 V

1 0 6

1 3 3

D 5

F D I N

3 4 C S Y C S

3 6

E 1 C S

D 0 5

1 0 7

1 3 4

D 6

F C S 1

3 4 C S M C

S P S L ( S M C )

D 0 6

8 8

T 1

3 7

1 0 2

1 3 5

D 7

E I

F C S 2

3 6 C R D A T

R D A T

D 0 7

D B U S 2 5 E , 3 6 D

+ 5 V

2 3 D M T I 1

9 5

1 0

C L 2

V D D

+ 2 5 V

2 3 D M T I 0

9 8

4 3

C L 1

V D D

9 9

9 7

C L B

V D D

L 9

L 1 0

L 1 1

L 1 2

1 0 0

1 1 4

3 2 A

R B

V D D

R 8 3

1 0 1

1 3 2

7 5 K

D I F

V D D

1 0 4

1 4 7

C 7 2

3 2 A , 3 4 C T G

T G

V D D

L 5 V

1 6 5

V D D

R 8 1

5 2

1 9 0

C 6 9

R D A 6 1

V D D

1 0 K F

5 6

2 0 1

3 2 B

V I D

E 5 V

C C 1 0 4

C P 1 I

V D D

5 5

3 2 D C P 3 I

C P 3 I

5 4

1 5

C P 4 I

V S S

G N D

E 0 V

5 3

3 8

R 7 6

C P N N

V S S

6 0

7 5 F

V S S

5 0

8 1

R D A 6

V S S

E 5 V

5 1

9 6

A V D D

V S S

C 5 5

C 5 6

C 6 0

C 8 4

C 8 5

C 8 6

C 8 8

C 8 9

R 7 9

5 8

1 0 5

C C 1 0 4

A V D D

V S S

1 0 0 F

4 9

1 1 9

R E F H

V S S

4 8

1 4 2

R E F L

V S S

4 7

1 5 6

R 8 0

C 6 5

C 6 8

C 6 7

C 6 6

A G N D

V S S

L 1 5

L 1 0 2 B

5 9

1 6 4

7 5 F

C C 1 0 4

A G N D

V S S

2 0 0

V S S

E 0 V

(FAX870MC/MFC970MC/FAX-930/

E 0 V

G N D

F G

Brother FAX-921, MFC-970MC, FAX-931 service manual Main PCB 1/6

Models: MFC-970MC FAX-931 FAX-921

M E X T L

M T X L

Main PCB 1/6

FAX-931)