Plotter does not recognize print head is installed or hangs on initialization.

Plotter displays one of the following: 

                  PRINT CARTRIDGES ARE ACCESSIBLE NOW
                  PLEASE INSTALL PRINT CARTRIDGES
                  CARTRIDGE ERROR: REPLACE K
                  CARTRIDGE ERROR: REPLACE C
                  CARTRIDGE ERROR: REPLACE M
                  CARTRIDGE ERROR: REPLACE Y

or, plotter will not complete initialization on power-up.


A.    If one of the above messages is displayed when a print cartridge has 
      already been installed, then perform the following:

      1.   Move the carriage assembly area to the exchange position by 
           perfoming the following steps:

           a.   With the dust cover closed, the media engage/release mechanism
                engaged, the plotter power is on, and the plotter displays 
                either: ONLINE or UNLOADED, press the ONLINE button to cause 
                the plotter to display: MANUAL.

           b.   Press the left arrow key on the plotter. The carriage assembly
                will move to the exchange position.

      2.   Inspect the Cartridge Free/Lock Knob, located in the lower left 
           of the carriage assembly. 

           a.   The Cartridge Free/Lock Knob has two positions: 
                Lock and Unlock. 
                
                i.   At the 3 o'clock position, the knob points to the 
                     word LOCK on the carriage assembly. 

                ii.  At the 6 o'clock position, the knob points to the 
                     word UNLOCK on the carriage assembly.

                iii. If the Cartridge Free/Lock Knob is turned too hard, it 
                     is possible for the controlling gear to jump out of 
                     alignment. If this should occur, the plotter requires
                     service to correct.

      3.   Inspect the electrical contact points of the print cartridge. 
           Perform the following:

           a.   Press down and rotate the Cartridge Free/Lock Knob to the 
                UNLOCK position and remove the print cartridges.

           b.   Turn off the plotter power.

           c.   With a cotton swab moistened with isopropyl alcohol, 
                clean the print head electrical contacts located on the 
                carriage assembly.

                Also, clean the print head electrical contacts located on 
                the print heads.

           d.   Reinstall the print heads into the carriage assembly,
                press down and rotate the Cartridge Free/Lock Knob to the 
                LOCK position, and close the dust cover.

           e.   Turn on the power to the plotter. 

           f.   If the plotter displays an error for only one print 
                cartridge, then there may be a problem with that 
                particular print head.

                i.    If the black cartridge is being used, there may 
                      be a problem with the bar code on the print head. 
                      Try using a piece of white correction tape or 
                      white correction fluid (such as Liquid Paper), 
                      available at local office supply stores, to cover 
                      the third bar code line (reading from left to right).  
                      Note that the first bar code line appears on the 
                      left-most edge of the label.
               
                                 K
                         | | | | |  vent
                             ^      hole
                         1 2 3 4 5 
               
                i.    The print head may be defective. Check by 
                      replacing the print head with another one. 

           g.   If the problem is still not resolved, the plotter requires 
                service.