Hikari H9199, Instruction Manual Book And Parts Book

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INSTRUCTION MANUAL
- 61 -
Problem Possible cause Page
9
Lower thread is tangled at
The sewing start.
Spinning of bobbin during
thread trimming
· Is the bobbin spinning direction correct when the lower thread is
being pulled
？
Set the bobbin so that is turns in the opposite direction to the
Rotary hook.
· Is there too much thread wound onto the bobbin ？
The bobbin winding amount should
Not be more that 80%.
· Is the anti-spin spring attached
？
Attach the anti-spin spring.
· Is the bobbin turning smoothly
？
If the bobbin is not turning smoothly, replace the bobbin.
· Is a bobbin other that the light-alloy bobbins specified
？
Use only bobbins which are specified by HIKARI.
41
41
41
41
10
Upper and lower threads
are breaking
· Is the needle bent or is the needle tip broken ？
Replace the needle if it is bent or broken.
· Is the needle properly installed
？
If it is incorrect, install the needle correctly.
· Is the machine properly threaded
？
If it is incorrect, thread the needle correctly.
· Is the rotary hook sufficiently lubricated
？
(7900,7901specifications)
If control plate displays “Please lubricating oil”, please
lubricating.
· Is the upper or lower thread tension too weak or too strong ？
Adjust the upper thread or lower thread tension.
· Is the upper thread may be loose because the thread take-up spring
operating range is too small
？
Adjust the position of the thread take-up spring.
·
Is the rotary hook, feed dog or other part damaged
？
If they are damaged, smooth them with an oiled grindstone or
replace the damaged parts.
·
Is the thread path damaged?
If the thread path is damaged, smooth it with sandpaper or
replace the damaged part.
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41
50
44
53
11
Incorrect thread trimming
（
Upper and lower threads
are both not being trimmed ）
· Is the fixed knife or movable knife damaged or worn ？
Replace the fixed knife or the movable knife.
12
Incorrect thread trimming
（
Upper thread or lower
thread is not being trimmed ）
· Is the needle properly installed ？
If it is incorrect, install the needle correctly.
· Is the fixed knife or the movable knife blunt
？
Replace the fixed knife or the movable knife.
Lower
thread