Check the balloon sensor
The balloon sensor may not be detecting the value.
If you have a loom from about 20 years ago, you can check on the panel whether the value of the balloon sensor is detected.
There are 4 patterns of undetectable causes.
1.Garbage has accumulated
Garbage can be mistaken for thread and cause short pick.
2.Balloon sensor distance is not appropriate
If the balloon sensor is too far from the length measuring band, it will not be able to detect the thread and will cause a long pick.
3.The balloon sensor is damaged
If there are scratches, it may cause misidentification or undetection.
4.The balloon sensor is broken
In rare cases, it may break.