Happy HCS2-1201-30, Maintenance Manual

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16 4
6-2-2 Trouble shooting (Thread break)
Trouble Factor Cause of trouble and measure Page
Thread break
Mechanical
11. No problem in rotary hook? 3-1-1
11-1 Clean it to remove lints. (23-2)
11-2 Furbish scratch. (23-2)
11-3
If backlash of bobbin case holder and outer hook grows bigger, replace them.
11-4 Replace.
12. No problem in rotary hook retainer?
12-1 Remove burr and scratch.
12-2 Adjust position.
3-5-2
13. No problem in needle?
13-1 Fix it properly .
3-1-2
13-2 Select proper size of needle to match thread thickness. 3-1-4
13-3 If tip of needle is warped or bent, replace. 3-1-1
13-4 Replace.
14. No problem in bobbin case?
14-1 Remove rust and scratch.
14-2 If thread guide spring is off, replace it.
15. No problem in bobbin?
15-1 Remove scratch (iron bobbin).
15-2 If distorted. replace it.
16. Is needle bar spring not broken?
16-1 Replace it.
3-3-7
17. Does needle bar make smooth movement?
17-1 If bent, replace it.
3-3-7
18. No backlash in moving head?
18-1 Adjust positioning roller shaft.
3-3-2
19. Needle doesn't drop in the center of needle hole.
19-1 Adjust positioning plate and adjust needle drop back and forth.
3-3-4
19-2
Adjust position of needle selection unit, then adjust needle drop right and left.
3-4-1
20. Is the lowest needle position proper?
20-1 Adjust mechanical lowest needle position.
3-2-3
20-2 Adjust electric lowest needle position. 4-2-1
21. Is needle height proper?
21-1 Adjust as specified.
3-3-6
22. Is rotary hook timing proper?
22-1 Adjust as specified.
3-5-1
23. Is clearance between needle and rotary hook proper?
23-1 Adjust as specified.
3-5-1
( ) ---Reference instruction book