Carriage traveling

Jim

HP-812C

As I try to print the cartridge tray travels back and forth continuously
on the cartridge carriage bar. Doesn't matter which of my computers it
is hooked up to nor whether I'm using LPT or USB.

Might this be a dirty position sensor or could this mean time has come
for replacement?

Tony

Jim <> wrote:
>HP-812C
>
>As I try to print the cartridge tray travels back and forth continuously
>on the cartridge carriage bar. Doesn't matter which of my computers it
>is hooked up to nor whether I'm using LPT or USB.
>
>Might this be a dirty position sensor or could this mean time has come
>for replacement?

Is the carriage "slamming" back and forth?
If so, the encoder strip may have come loose at one end.
The encoder strip is a piece of mylar or similar that runs the entire width of
the printer. It is about 6 milimetres wide and is almost transparent with thin
lines on it. This tells the carriage exactly where it is when printing. I
haven't seen a sensor fail but have seen many encoder strips come loose. One
end is spring loaded and the other is hooked onto the chassis.
I guess it is possible for the sensor to have become contaminated with ink, to
get at it you would have to remove the covers, the encoder strip and the
carriage bar then access the carriage. The sensor is at the rear of the
carriage.
Tony
MS MVP Printing/Imaging