Lincoln Electric Square Wave TIG 255 Manual - Troubleshooting Circuit Board Issues

ELECTRICAL DIAGRAMS

G-11

TOC

CONTROL BOARD SCHEMATIC — SQUARE WAVE TIG 255

(G2150)

to Section

to Master

T O A 4 8 2 . 2

Return

R 6 7

R 1 3 6

R 1 3 7

T A G E F E E D B A C K

Z E R O C R O S S

SCR 2,4

SCR 1,3

4 7 5 K

1 5 . 0 K

1 0 0 K

V O

D 3 0

E L E C T R O D E

- 1 5 V

J 6

1 3

R 5 5

D 2 2

D 2 1

1 4

1 . 0 0 M

X 1 1

R 3 9

L E G E N D

C 4 9

04N 1

K5. 74

1 2

1 0 0 K

( G R O U N D A N D + 5 V N E T S )

. 0 0 4 7

N G N D

V o l t a g e F B

3 0 0 0 V

C 7 9

K00 1

82R

92R

03R

13R

7 5 0 p

44R

I O G N D

P R O C E S S O R I O C O M M O N

D 1 1

D 1 0

1 0 0 0 V

R 4 0

D 7 6

004

N G N D

4 7 . 5 K

L G N D

L O G I C C O M M O N

W O R K

V O L T _ F B

1 2

R 3 8

N G N D

N O I S Y C O M M O N

J 6

C 8 0

1 . 0 0 M

X 1 1

R 6 9

J 8

L C D G N D

D I S P L A Y C O M M O N

A U X S C R 1 , 2

7 5 0 p

1 . 0 0 K

1 0 0 0 V

C 8 1

X 3 1 G N D

X 3 1 C O M M O N

D 5 1

D 5 4

1 6 V A C

D Z 1 6

+ 1 5 V

D Z 1 4

23R

0 . 1

X 3 1

D 7 7

N G N D

1 2 V

4 7 . 5 K

5 0 V

X 3 2 G N D

X 3 2 C O M M O N

1 W

( 1 o f 5 X F M R

1 0 0

TOC

s e c o n d a r y

C 2 8

TOC

D 5 3

D 4 9

w i n d i n g s )

I O G N D

C 2 9

2 7

N G N D

I O + 5 V

P R O C E S S O R I O + 5 V S U P P L Y

12R

42R

961 R

62R

381 R

071 R

I O + 5 V

2 7

3 5 V

D Z 1 7

J 8

D Z 1 5

3 5 V

A U X S C R 1 , 2

1 2 V

L + 5 V

L O G I C + 5 V S U P P L Y

O C I 4

1 2

4 O C I 5

1 2 V

1 W

N + 5 V

N O I S Y + 5 V S U P P L Y

C N Y 1 7 - 3

to Section

to Master

K574

D Z 7

K574

N G N D

4 . 7 5 K

32R

762

91R

762

56R

D Z 1 0

L C D + 5 V

D I S P L A Y + 5 V S U P P L Y

Q 4

3 0 V

Q 2

3 0 V

Q 1

Z E R O C R O S S

X 3 1 _ + 5 V

X 3 1 + 5 V S U P P L Y

1 A

1 W

1 A

1 W

1 0 0 V

X 1 0

6 0 0 m A

J 5

1 . 0 0 K

D Z 4

S C R 1 G A T E

1 . 0 0 K

D Z 8

S C R 2 G A T E

4 0 V

X 3 2 _ + 5 V

X 3 2 + 5 V S U P P L Y

R 2 1 4

R 1 9 9

1 8 V

D 5 2

1 . 0 0 K

1 8 V

D 5 9

1 W

D 5 8

1 . 0 0 K

D 9 9

D 5 0

1 . 0 0 K

C 6 5

1 0 0 K

C 4 1

4 . 7

D 1 0 0

R200 4 7 5 K

24R

N + 5 V

L + 5 V

I O + 5 V

L C D + 5 V X 3 1 _ + 5 V

X 3 2 _ + 5 V

52R

311R

21R

511R

411R

3 5 V

J 5

Return

J 5

S C R 2C A T H O D E

C 6 6

S C R 1 C A T H O D E

I O + 5 V

4 . 7

D 1 0 1

3 5 V

+ 1 5 V

I O G N D

J 8

C 3 8

A U X S C R 3

A U X S C R 4

D 4 7

D 4 8

. 1

1 . 0 0 K

D 1

D 5 5

5 0 V

+ 1 5 V

1 6 V A C

+ 1 5 V

1 6 V A C

D 2 5

D 2 3

Q 5

X 1 0

R 1 8 4

6 0 0 m A

( 1 o f 5 X F M R

1 0 0

4 0 V

s e c o n d a r y

1 0 0

s e c o n d a r y

Q 1 7

2 6 7

C 2 7

D 4 6

D 4 5

w i n d i n g s )

D 6

w i n d i n g s )

C 3 0

D 5 6

S 1 8 6 4 7 - 2

I N

O U T

D 5

D 4

R 2 7

R 2 2

6 0 0 m A

81R

41R

61R

2 7

71R

81R

171R

X 1 5

X 1 2

J 8

A U X S C R 3

2 7

2 2 1 K

1 0 K

4 0 V

3 5 V

J 8

A U X S C R 4

J 8

I N

7 8 1 5

O U T

7 8 0 5

4 O C I 3

1 1

4 O C I 6

3 5 V

1 0

I O G N D

G N D

D 7 2

C 4 4

431

2 . 2 1 K

C N Y 1 7 - 3

D Z 6

C 6 7

C 4 2

C 4 7

1 . 0

61R

K57 4

611R

K574

D Z 1

. 0 0 4 7

3 5 V

1 . 0

D 7 1

3 5 V

I O G N D

181

762

Q 6

3 0 V

46R

762

Q 1 2

1 W

3 0 V

3 0 0 0 V

1 0 0 0

3 5 V

I O G N D

1 A

1 W

1 0 0 V

3 6 V A C C T

C T

J 8

1 0 0 V

J 5

D Z 5

S C R 3 G A T E

1 . 0 0 K

S C R 4 G A T E

C 6 8

C 4 3

D 4 4

( 1 o f 5 X F M R

2 0

C 4 8

02R

1 8 V

D Z 9

D 7

s e c o n d a r y

. 0 0 4 7

00.1

1 W

811 R

1 8 V

5 0 V

G N D

1 . 0

D 4 3

211 R

1 . 0 0 K

w i n d i n g s )

3 0 0 0 V

3 5 V

D 7 3

1 W

D 5 7

1 . 0 0 K

J 8

I O + 5 V

J 5

X 1 6

S C R 3C A T H O D E

J 5

TOC

D 3

D 2

I N

O U T

S C R 4C A T H O D E

7 9 1 5

C 4 5

. 1

5 0 V

1 . 0 0 K

D 9 2

D 2 4

522R

Q 3

Section

Master

N G N D L G N D

X 1 0

R 1 8 5

6 0 0 m A

- 1 5 V

2 6 7

4 0 V

V B

L C D G N D

X 3 1 G N D

Q 1 6

I O G N D

X 3 2 G N D

R 6 3

R 9

6 0 0 m A

2 2 1 K

1 0 K

4 0 V

I O G N D

1 6 V A C

2.2

12R

1 1

X 1 0

1 0

L + 5 V

Return

G E N E R A L I N F O R M A T I O N

1 6 V A C

I O G N D

+ 1 5 V

X 3 1 _ + 5 V

X 3 2 _ + 5 V

C A P A C I T O R S =

M F D ( . 0 2 2 / 5 0 V

U N L E S S O T H E R W I S E S P E C I F I E D )

X 1 0

R E S I S T O R S = O h m s (

1 / 4 W U N L E S S O T H E R W I S E S P E C I F I E D )

1 6 V A C

X 3 1

D I O D E S =

1 A , 4 0 0 V

( U N L E S S O T H E R W I S E S P E C I F I E D )

1 0 K

1 2 0 V A C

V d d

2 6

2 0

1 4

2 0

C 1 1

C 1 4

1 3

X 1 0

1 2

12R

1 0 K

X 3

C 3

X 1 0

0 . 1

S Q U A R E W A V E T I G 2 5 5 C O N T R O L B O A R D

2 4 V A C

X 2 0

C 1 0

C 7

X 2 1

C 6 9

X 2 2

C 7 0

5 0 V

0 . 1

7 4 H C 1 4

0 . 1

X 1 1

X 1 4

X 3 1

M C 6 8 H C 1 1

5 0 V

7 4 H C 5 7 3

5 0 V

7 4 H C 5 7 3

0 . 1

5 0 V

X 3 1

X 3 2

1 0 K

5 0 V

7 4 H C 5 7 3

C 1 2

C 1 5

T C F 6 0 0 0

A 4 8 2 . 1

0 1 / 0 3 / 9 4

3 3 0 7 4 A

V s s

1 0

0 . 1

1 0

1 1

5 0 V

1 1

5 0 V

3 6 V A C C . T .

I O G N D

X 3 2

		X 3 1 G N D	X 3 2 G N D
	L G N D L G N D L G N D	L G N D
	L G N D L G N D L G N D
		- 1 5 V
C O N T R O L T R A N S F O R M E R

TOC	TOC
Section	Master	NOTE: Lincoln Electric assumes no responsibility for liabilities resulting from board level troubleshooting. PC Board

to	to	repairs will invalidate your factory warranty. This Printed Circuit Board schematic is provided for reference only. It may not
to	to	be totally applicable to your machine's specific PC board version. This diagram is intended to provide general information
Return	Return
Return	Return	regarding PC board function. Lincoln Electric discourages board level troubleshooting and repair since it may compromise

		the quality of the design and may result in Danger to the Machine Operator or Technician. Improper PC board repairs
		could result in damage to the machine.

Lincoln Electric Troubleshooting Lincoln Square Wave TIG 255 Issues and Circuit Board Problems

Models: SVM100-A

ELECTRICAL DIAGRAMS

(G2150)

3 6 V A C C T

G E N E R A L I N F O R M A T I O N

A 4 8 2 . 1

SQUARE WAVE TIG 255