Getting Sparks shapes and White Lines when Printing

[masterdz]

Hello guys

When I print from my Xerox 550 machine, in colors or Black, first 3 or 4 papers are OK, but then I get white sparks and white lines on the print on the left down side of the paper on A3 or A4 size, I cleaned the ROS, 2nd BTR, Belt station but remains the same, I tried to print CMYK each color on a paper I get the white sparks & white lines on all colors, Now I can't figure out what is the problem :/
I attached pictures of the problem in the attachements

please help

[masterdz]

Problem solved, problem was we had new belt from Aliexpress website and it seems to be broken, so we put the old belt back and sparkles gone

Thank you guys