There are repeated dots every 75mm on the print

Try to print clean page ,
Print a cleaning page During the printing process, paper, toner, and dust particles can accumulate inside the printer and can cause print quality issues such as toner specks or spatter, smears, streaks, lines or repeating marks. Follow these steps to clean the printer's paper path.

1. Load copier-grade paper (not bond, heavy, or rough paper).
2. On the printer's control panel, touch the Menu button.
3. Touch Configure Device .
4. Touch Print Quality .
5. Touch Process Cleaning Page .

A Cleaning message appears on the printer control panel display while the cleaning is taking place. The cleaning process takes a few minutes to complete. Do not turn the printer off until the cleaning process has finished. A page will be printed when the task is complete. Discard the page. You might need to repeat the cleaning process to thoroughly clean the printer. Print a few more pages to see if the problem is resolved.

Repeating Defects:
• 2 per page (IBM, Lexmark printers only)
(5" or 125mm spacing)
u Replace toner cartridge (drum defect)
• 3 to 4 per page
(3" to 3.7" or 75mm to 94mm spacing)
u Replace toner cartridge (drum defect)
u Replace fuser (fuser roller/sleeve defect)
u Get printer service

• 5 to 7 per page
(1.3" to 2.5" or
32mm to 63mm spacing)
u Replace toner cartridge
(developer
defect)
u Replace fuser
(fuser roller/
sleeve defect)
u Get printer
service

• 7 per page
(1.5" to 1.7" or 38mm to 43mm spacing)
u Replace toner cartridge
(PCR defect)

If I could be of further assistance, let me know. If this helps or solves the issue, please rate it and give a testimonial for my response

Thanks, Joe


I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_8b8c2cd6ce148309

HI

Just go to printer icon and click right mouse. Choose printing preferences and choose print quality. Setting quality to 600x600 dpi quality. It will helps you solve your problem.

regards

dots printed are from the cartridge, you proved that with the change to the old one. If the fuser was faulty, it would repeat the dot 2.5 times down an 8.5 x 11 page
Replace the cartridge and please use HP , remanufactured cartridges fail prematurley and usually wind up costnig more in service and repair/exchanges.

Did you replace the toner? dirty print out might be the sign of low toner or faulty drum unit.
But if the dots are repeating on same line..then most probably it's the drum or fuser problem.

is the dot repeating... if yes.. then try replacing the toner unit.. normally the dot is on the drum..

that dotted line is produced by one of you toner cartridges,put attention to what color the dots are and replace the cartridge.
also there is an option in the menu to disable the cartridge check ,do that under "diagnostics menu" and start taking 3 cartridges the first time and print something,check if dots are present,if not put another cartridge print something and check ,repeat process until you find the defective one.

The four coloured dots are what is known in the trade as "Traffic Lights". They happen when the photocuductor (PCU) drum gets scratched. If you do a black only print you will only get a black dot, if you do a print with some colour in it you will get all four dots repeated at 150.41mm (PCU drum circumference) intervals. The best answer would be to replace the PCU but it is expensive. The alternative is to take out the PCU, find the scratch and try to polish it out with a very soft cloth. This will only work on the lightest of scratches. Be very careful not to scratch the drum further and avoid shining any bright light on it as it will damage the photo-sensitive surface (normal ambient light is OK).

If toner leaked into the machine and got on the fuser that could cause this, but the dots would go away after a few prints. Try another drum unit.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=125&prodSeriesId=500083&prodTypeId=18972&prodSeriesId=500083&objectID=c00506714

Give this a shot.