Newsgroups: comp.periphs.printers


>> I'm having a problem printing. It did the test printout but nothing
>> came out on the page. I cleaned the cartridge head and the little
>> dohickey it comes into contact with in the printhead very thouroughly
>> (with alcohol and swabs, repeatedly), and the printing got much better
>> but just faded out again. I'll be getting a new cartridge tomorrow and
>> I'll try that, but it seems to me that the problem is in the printhead
>> in the printer, and, though I clean it all I can, I can't reach the
>> other side of it, the side up against the platten. Can this be reached
>> in some easy way?

Sounds like you have a dead ink cartridge.  Try a new one.  If it has
been sitting around for a long while in the printer, it is probably
dead.  

The only other point that is worth cleaning is the elctrical contact
between the ink cartridge and the carriage in which it sits.  If the
printer has been sitting around for a while, this may be dusty or
corroded.  Try cleaning it with a bit of alcohol.  There is no need to
get between the carriage and the platen.  That is just a bit of plastic.

>> Is there a FAQ anywhere that can explain to me how this works,

Not that I know of.

>> specifically, by what mechanism is the ink sprayed onto the right
>> spot? I'm just curious.

As the ink cartridge is moved over the paper, an electric current is
passed into it via the contacts on the carriage.  This is used to
heat ink in a chamber within the ink cartridge.  A portion of the ink
boils forcing the remainder out of the face of the ink cartridge and
onto the paper.  The steam then condenses, sucking more ink into the
chamber.  The ThinkJet has eight chambers arranged vertically that are
used to produce a line of characters.

>> I have the manual, but the manual only talks about a parellel port
>> version, yet I have a serial port on mine. There's 5 dip switches to
>> control the RS-232 port (in addition to the 8 dip switches for the
>> mode), but I have no idea what any of them do. Can anyone help me?

Interestingly, this question came up recently in an internal HP news
group.  Here is the information that was posted there:

  Switch#  Meaning       Position  Condition      Default
  1        Handshake       up      Track DTR
                           dn      Xon/Xoff        Yes
  2,3      Parity        dn,dn     none            Yes
                         dn,up     odd
                         up,dn     even
                         up,up     one
  4,5      Baud          dn,dn     9600            Yes
                         dn,up     19,200
                         up,dn     2400
                         up,up     1200

>> Finally, the manual mentions a maintenence giude, which I take it is a
>> seperate book explaining how to repair the thing. Anyone know where I
>> can get one of these things, and how much they cost. I would be
>> interested in having that around.

The 2225 service manual is listed on the HP parts price list as part
number 02225-90079 and costing $100.  You may be interested in the
2225D owners manual which is listed as part number 02229-90080 and
costing $12.  The latter is the version of the manual you have, but
for the RS-232 version of the printer and includes the switch
settings.

	Mark Simms

----------------------------------------------------------------------
Opinions expressed are my own and are not intended to be an official
statement by Hewlett-Packard Company
----------------------------------------------------------------------
Name:         Mark Simms
Profession:   Software Engineer
Organization: Hewlett-Packard Computer Peripherals Division
Unix-mail:    mark@hpcpbla.bri.hp.com
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From: mark@hpcpbla.bri.hp.com (Mark Simms)
Date: Wed, 27 Jan 1993 15:15:33 GMT
Subject: Re: HP-7585 plotter
Organization: HP Computer Peripherals Bristol, UK