7–5Interfaces
Alternate Terminating Resistors
For
parallel interface configurations, the printer is equipped with 1K ohm pullup terminating resistors
located
at board coordinates
20D on the Controller PCBA. (The printer outputs are also pulled up with
a 1K resistor pack on the Controller
.) Generally
, the 1K
ohm terminating resistors are suitable for most
applications.
If, however
, the standard terminating resistor
pack is not compatible with the particular
interface
driver requirements of the host, other values of pullup/pulldown resistors may be
necessary
.
Printronix
provides the 220 ohm pullup and 330 ohm pulldown alternate terminating resistors. If the
220
ohm pullup resistor is used, the 330 ohm pulldown resistor should be used with it.
Installing
the alternate terminating resistors requires three main procedures listed below and explained
in
the following sections.
•Remove
Printer Cabinet
(Pedestal Model) or Remove Paper Guide (Floor Cabinet Model)
•Remove Controller Board and Install T
erminating Resistors
•Restore Printer to Operation

Remove Printer Cabinet (Pedestal Model)

To remove the printer cabinet, perform the following steps and refer to Figure 7–1.
1. Turn off the printer power, disconnect the AC power cord, and open the printer cover (A).
2. Loosen
the captive screw securing the control panel (B) and the two captive screws securing the
display control panel (C) to the printer. Set the panels inside printer cabinet.
3. Loosen
the two Phillips head screws
(D) securing the cabinet cover to the printer base located at
the inside front right and left corners.
4. Loosen the two Phillips head screws and washers (E) on the outside rear of the cabinet cover.
5. Close printer cover (A) and carefully lift the cabinet off printer base.
6. Proceed to Remove the Controller Board section on page 7–8.

Remove Paper Guide Assembly (Floor Cabinet Model)

To remove the paper guide assembly from the floor cabinet model, perform the following steps and
refer to Figure 7–2.
1. Turn
of
f the printer power
, disconnect the AC power cord, and open the printer cover and the rear
door.
2. From
the front of printer
, loosen, but do
not remove, the two upper attachment screws (A) secur
-
ing the paper guide assembly (B) to the printer base (C).
3. From
the rear of printer
, remove lower four attachment
screws (D) securing the paper guide as
-
sembly (B) to the printer base (C).
4. Lift off the Paper Guide Assembly (B).