My IR-printer 82240A doesn´t print right

[Matti Övermark]

I have an HP IR printer of the first model (A). It has worked flawlessly even though I bought it second hand. S/N is 272S10269.

Now there is one or maybe rows missing on the output on paper.
* indicates successful printing, - no printing.

******      ***       ***********

*      *   *    *          *

**     *   *    *          *

*******    ******          *          and so on   

*      *   *    *          *

       -   -    -          -

       -   -    -          -

******     *    *          *

Other data.

* No change with fresh/old batteries, neither when using charger.

* Version D as indicated last in the testpage.

* Prints as requested from all calculators that I have access to.

I tried to see on Randys (fixthatcalc) page, but I found no help.

Anyone know how to solve it?

TIA Matti 

[Michael de Estrada]

Pending a reply from one of the more expert forum members, I'm going to suggest that the print head has some bad elements. Either that or possibly the connector ribbon has some broken lines or bad connections.

[Tony Duell]

The printhead consists of a vertical column of elements (each corresponding to a dot row), and it appears that some of yours have failed.

I would open it up, disconnect the printhead ribbon from the PCB and check the elements for continuity. If some are open-circuit, you need a new print mechanism (I don't think the printhead is a replacable part, alas).

If the printhead checks out, it could be the driver chip on the PCB (I think that's a standard part and can be replaced) or the microcontroller (custom programmed, only source is another similar printer).

There's a schematic of the 82240B on the HPCC CD-ROM. There are differences, of course, but it might be a start.