yellow toner dots on low 60-65 gsm coated paper

hi

when printing on 2 side coated 60 or 65 gsm paper ,i can see yellow fine toner dots scattered on the printed result or i can say light dots mostly appearing on the dark solid backgrounds.
any one had this problem?
any solution?

thanks

 

this is happening on imagepress 6010

 

Is this the government mandated yellow dot pattern (anti counterfeit), or a more random scatter of yellow dots?

 

Yeah but there is no way "government mandated yellow dot pattern" is printed only on second side of the document... Must be something else. What happens if you run something thicker? I would imagine that running thin paper that has a little more moisture than it should would turn paper to be wavy and while it goes trough second pass it picks-up some toner dust deposits on paper path... Pretty much the only 2 things that touch second side of the paper are Transfer roller or belt and pressure roller. Look at them both - is there any toner deposits? I think big machine like this should have a transfer roller/belt cleaning device - is working correctly? Way to check is to turn it and see if surface being nicely cleaned. Also if machine has descent mileage there could be simple toner deposits that are dripping on paper occasionally... Make sure that machine is clean and NO Air can you will blow the dust from one spot to another possible creating bigger issues, 3M vacuum cleaner has to be used.

 

only random scatter of yellow dots and not related to goverment.
it appears on low gsm paper only.

 

If you look at other paper stocks under an eye glass you should be able to see the yellow dots.

All machines have it and its unique to your machine.