LJ 4000 multiple thin vertical lines

[tspafford]

We have a 6-year-old LJ 4000 TN. It has been printing w/o problem until now (181K pages).

Every print now, even self test, prints a background of absolutely evenly-spaced, thin vertical black lines the entire height&width of page. Also does print desired output on top of the lines.

The spacing is about 18.5 lines/inch.

Chanhes toner cartridge, cleaned corona wire - nada.

I'm thinking formatter. yes?

TIA

[ptjeff1]

Check out the fuser to see if there is anything funky going on with the sleeve, but you are probably right, it sounds like the formatter (video lines).