How to troubleshoot the embedded clamp machine

Troubleshooting case of embedded clamping machine
A certain enterprise produces a batch of washed foreign trade shirts. After inspection by the inspector, it was found that two to three out of every hundred shirts had skipped stitches through cross stitching. After washing, they scattered and caused the products to be unqualified
Defect shape:
Zheng Buhe doesn't seem to have skipped stitches, but when he touched the cross stitch with his fingers, there was scattering. He didn't pay much attention. After washing with water, he appeared. Every hundred pieces reached two to three pieces
Fault analysis:
1. This machine needle clip has the right needle in front and the left needle in the back. Most of our factory's machines have the left needle in front and the right needle in the back. No such problem has been found, so there is doubt about the structure of this machine
2. This machine has undergone multiple machine repairs and has also been repaired by maintenance personnel from a sister company. Therefore, there is doubt that it was a congenital problem when the machine was manufactured
3. Due to the above issues, a comprehensive inspection of this machine is required to restore the factory's factory data values
Defect repair:
1. After adjusting various data values using a vernier caliper to refer to the revised instruction manual of DA-9270 (Standard Adjustment Content), they all reached the standard. However, after trial use, they were not satisfactory
2. Since the adjustment in all aspects is not ideal, we began to question the front and rear travel of the needle hook. Therefore, we adjusted the forward/backward cam of the needle hook to make the front and rear travel of the needle hook slightly smaller. The needle hook slightly collides when it is hooked. The needle does not touch and slightly collides when it is wiped down on the return journey. After being used, we have investigated for nearly 10 days and found no such problem again
Problem closure;
This problem is caused by a slightly larger cycle travel of the hook needle before and after