HP Draftmaster RX pen plotter needs love

[Alexandre Souza]

How is the power supply? All rails ok? Input/output capacitors not bulged
nor leaked?

2016-11-11 21:36 GMT-02:00 Michael Newton <michael.newton at gmail.com>:

> I acquired a working HP Draftmaster RX (HP part # 7596B).
>
> An awesome machine, 36" roll feed and 8 pens, complete with several pen
> carousels, user manual, and hundreds of working pens.
>
> I was very excited to make a splash in the art world with this thing. I did
> get it to perfectly draw a 3 color demo page from the front panel.
>
> Thereafter it started displaying errors on the display such as "200" which
> means it needs "mechanical calibration".
>
> Thanks to hpmuseum.net I acquired the service manual
> <http://www.hpmuseum.net/document.php?hwfile=1292>, which catalogs many
> calibrations and self-tests to run from the front panel, including the
> aforementioned "mechanical calibration".
>
> So I power up with the appropriate front panel keys depressed to run this
> calibration. The paper drive motor starts making noise, but the paper
> rollers aren't turning, and the LCD display is blank.
>
> Since that moment, the LCD display is always blank so it is currently a
> boat anchor.
>
> It's a terribly sad state of affairs. I have basic electronics and
> mechanical skills and an oscilloscope so following the troubleshooting
> procedures in the manual I might be able to identify a part to replace. But
> of course, parts for sale online are are rare, expensive, used and probably
> untested.
>
> Probably better would be lower-level repair of whatever parts are faulty
> but that's probably more than I can manage at my skill level.
>
> I'm in Seattle, WA. Is there anyone alive in the pacific NW who will pay a
> visit and help me fix this thing? (The only company I found that admits to
> working on pen plotters is 360tech in Austin, TX.)
>
> Or someone elsewhere I could ship electronics parts to for test and repair?
> Or provide guidance, or help in any form at all?
>
> thanks
> M.
>