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HP 8000 uneven lines on trailing edge

Posted: Tue Jan 11, 2022 4:43 pm
by jedi4342
Has anyone seen the trailing edge of an 8000 have a jagged edge about 1 inch long then the next inch will be about an 1/8 of an inch from making a straight line. All the way down the trailing edge.
-----____------_____--------______--------______ Looks like this

Re: HP 8000 uneven lines on trailing edge

Posted: Mon Mar 14, 2022 3:01 pm
by MrXL
This is a couple months old, but figure I would share my knowledge on it.

Since the Dyes on the PH are staggered, you get this pattern when the printer shuts down the heads abruptly to prevent printing on the belt. The cause of this is usually related to the paper not being where it's supposed to be when expected. This could mean the stacker is grabbing too fast, vac is clogged, or even dirty output sensors. I would send jobs to the basket to see if it does there. If it does, it's not outoput, and could mean dirty belts or clogged vac holes. If the pattern happens in the middle of prints, that could be an issue with the Analog encoder (loose/cracked housing, dirty encoder disc).

Outside of that, it could be an issue with page length or media advance.

Re: HP 8000 uneven lines on trailing edge

Posted: Tue Mar 15, 2022 3:59 pm
by jedi4342
Have already done the page length and media advance, TOF calibration, have run the Roll assist friction calibration, Feed roller calibration, and running the drawer calibration. Replaced a couple of sensors. One on the stacker and the TOF sensor.