Again and again got a error of sc329 .......how to fix

Sc 322 is laser synchronization error Possible Cause : 1- Poor connection between the LD unit and the BICU board 2-Damaged cable between BICU and LD unit 3-LD unit out of position 4-LD unit defective 5-BICU board defective the first thing u can do is clean the laser unit , it could be dirty

THIS VIDEO SHOW HOW FIX IT
https://youtu.be/-DGnULMHtD4

change the td sensor below the developer unit or if possibly change the complete developer unit

LD unit beam pitch adjustment incorrectly.

SC329: Laser beam pitch adjustment error (B)
The LD unit HP sensor does not detect an on condition while changing the LD unit position for correcting the LD position or changing the dpi.
Laser beam pitch adjustment (SP2109-3/4 wasn't performed after a NVRAM clear; SP2109-1 ~ 4 not performed after replacing the LD unit; LD unit movement blocked because of incorrect connector routing

still sc329 error

HOPE YOU SPEAK ENGLISH the error is due to the laser unit malfunction..after memory clear usually..you need to press the yellow clear button then 107 then hold down the stop/cancel button for 5 secs till the screen changes.. then copier sp section 2 drum then look for laser pitch beam adjustment you need the 400dpi and 600dpi initialisation to be done.. this should clear it then turn off the machine and wait 10 secs and turn back on.. hope this helps ..Adios

Hello sir; Sometime this problem can be reset, just let's try, ; Press " clear mode ", "107", "stop/clear" key until screen show out sp mode then turn power off and back on again.

Did this happen after the machine was serviced? this is typically when it would occur...."LD pitch error"
Perform LD pitch adjustment with SP109-3, and SP109-4 (400dpi & 600dpi) or the ribbon cable on LD unit is blocking proper movement of the unit.

Never heard of this happening to five machines before.  Check the connections in the laser unit.