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HP-9000s serious printing problem

Quix

New Member
Hello to all.
After changing dampers (carefully removing the carriage board, disconnecting a re-connecting tubings and wires) the printer seems to be in some kind of short circuit.
It performs correctly all checkings (no error messages on panel), measures correctly the media and performs cleaning cycle; but when any test-print is performed or when any file is sent to print, all printheads print at 100% (all six printheads fire continuosly while carriage is moving); since the home position of the carriage to the end. (it also prints outside media borders)
Once I had this problem when solvent got into one printhead's connector; but it was corrected by cleaning it. Now it happens in the six PH's at once.
Does anyone know what the problem might be?
 

Quix

New Member
Sorry. English isn't my native language, so maybe I didn't make myself clear.
The problem was that all noozles in all six printheads fired contiuosly, not defining any image, but printing wide bands all over the media, even exceding the borders.
I cheched all connections and still got the same issue.
The encoder band got dirty, and the problem dissappeared after cleaning it.
But I'm still not sure that was the real problem.
 

Mspec

New Member
when the encoder strip or reader on any printer gets dirty it causes pulses to be missed. There is a crazy amount of communication going on between the carriage of a printer and the main electronics. The carriage is litterally saying "I am at this point, what jets should I fire here?" as it goes back and forth. A few missed pulses can get the two boards out of synch, and the result is a data purge. Think of it as a printer version blue screen.

There is a fine line between missing a few pulses, and missing a bunch. Miss a few, and you get nozzles firing all over the place, miss a bunch and the printer will falsely detect a media jam, or scan axis motor error.

It is possible that you corrected this issue by cleaning the strip, or while messing with the carriage you may have shored up a flaky data cable connector on one of the printhead interconnect boards. Either issue could have been the cause.
 
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