Here's a printer fix that I'd like to publicize, but I can't
find a good place on the Web to post it. So maybe someone
here do that for me.
Some HP printers have a strip of "plastic linguini" behind the
printhead. The strip has barcode-like markings that the
printhead employs to position itself precisely.
Most people here know that HP printer problems can sometimes
be cured by simply wiping that plastic strip. I've myself have
used that trick to cure several problems.
But I've had a few problems that couldn't be cured that way.
Most recent was one where I kept getting false "out of paper"
error messages.
My printer, incidently, is an HP 648C.
After I cleaned the plastic strip several times to no avail,
it finally dawned on me that there's another element involved
in reading that guide strip: The electric eye on the back of
the print head. The electric eye can get dirty, too.
So I decided to clean the electric eye.
First, I attempted to slip a wet piece of printing paper between
the plastic strip and where I figured the electric eye is. But
the paper was too thick.
Then I tried putting a few beads of water on the plastic strip,
and then running the printhead back and forth over the wet
spots. While doing so, I pulled the plastic strip forward
to help the water make contact with the electric eye. Then,
just to make doubly sure, I did the same thing again while
pushing the plastic strip in the opposite direction.
That cured the problem.
Before this, I was getting a "paper out" error every page or
two. After this, the problem didn't recur. I've now printed
about fifty pages without any error messages or problems.
"Roy Lipscomb" <lipscomb@ripco.com> wrote in message
news:f0iraj$blk$1@e250.ripco.com...
[snip]
> Then I tried putting a few beads of water on the plastic strip,
> and then running the printhead back and forth over the wet
> spots. While doing so, I pulled the plastic strip forward
> to help the water make contact with the electric eye. Then,
> just to make doubly sure, I did the same thing again while
> pushing the plastic strip in the opposite direction.
>
> That cured the problem.
>
> Before this, I was getting a "paper out" error every page or
> two. After this, the problem didn't recur. I've now printed
> about fifty pages without any error messages or problems.
Interesting, but a coincidence. The encoder described is related to the
side to side movement of the carriage. There is a similar sensor for the
paper movement direction, but it uses a small encoder disk (a couple inches
in diameter). There is also a paper sensor that uses a sensor that looks
much like the others, but is positioned to be in the paper path. My guess
is that in opening the lid and moving things around to clean the carriage
encoder you probably dislodged a bit of paper debris in the paper path
sensor.
On Apr 23, 12:44 pm, Roy Lipscomb <lipsc...@ripco.com> wrote:
> Here's a printer fix that I'd like to publicize, but I can't
> find a good place on the Web to post it. So maybe someone
> here do that for me.
>
> Some HP printers have a strip of "plastic linguini" behind the
> printhead. The strip has barcode-like markings that the
> printhead employs to position itself precisely.
>
> Most people here know that HP printer problems can sometimes
> be cured by simply wiping that plastic strip. I've myself have
> used that trick to cure several problems.
>
> But I've had a few problems that couldn't be cured that way.
> Most recent was one where I kept getting false "out of paper"
> error messages.
>
> My printer, incidently, is an HP 648C.
>
> After I cleaned the plastic strip several times to no avail,
> it finally dawned on me that there's another element involved
> in reading that guide strip: The electric eye on the back of
> the print head. The electric eye can get dirty, too.
>
> So I decided to clean the electric eye.
>
> First, I attempted to slip a wet piece of printing paper between
> the plastic strip and where I figured the electric eye is. But
> the paper was too thick.
>
> Then I tried putting a few beads of water on the plastic strip,
> and then running the printhead back and forth over the wet
> spots. While doing so, I pulled the plastic strip forward
> to help the water make contact with the electric eye. Then,
> just to make doubly sure, I did the same thing again while
> pushing the plastic strip in the opposite direction.
>
> That cured the problem.
>
> Before this, I was getting a "paper out" error every page or
> two. After this, the problem didn't recur. I've now printed
> about fifty pages without any error messages or problems.
>
> Hope this tip is useful to someone else!
>
> --
It is not a good idea to use water on these sensors, as they may short/
over-load other components. Air-in-a-can would be a better choice.
Hi, nice solution I will try that. Actually I recently found a great tech
support site that helped me deal with my printers problems. They also have
free live chat support so I just chat with won of their expert and together
we found a solution.
Here's another fix for HP printer problems 
Linear Mode
