Printronix P9012, Maintenance Manual

Page: 94 / 256

5–10 Alignments and Adjustments
Shuttle and Counterweight Spring Adjustment
(Figure 5–4)
NOTE: Spring force adjustments may be made with or without a force
gauge. The procedure on page 5–6 describes the use of a force
gauge and is preferred over the following.
NOTE: Although the following procedure is not recommended, it may be
performed if excessive rattle is detected under the cam cover and it
is not possible to perform the procedure on page 5–6. Such rattle
indicates incorrect spring force, which can result in impaired print
quality.
1. Open the cover.
2. Loosen two screws (1). Remove the cam cover (2) and the attached
gasket (3).
3. Inspect the area around the shuttle spring (4) and the counterweight
spring (5) for shims that may have broken or come loose. Replace any
loose shims per steps 6 and 7 below.
4. Set the AC power switch to the ON position. Run the printer using a
shuttle/ribbon test to keep the shuttle moving as necessary.
5. Loosen screw (9) about three turns. With the screwdriver, press in on the
loosened screw to apply heavy pressure to the right side of the
counterweight (6). Check for rattle.
a. If the rattle does not change, go to step 6.
b. If the rattle decreases, go to step 7.
6. Install a shuttle spring shim (0.01 in) as follows:
NOTE: More than one shim may be required to obtain the desired effect.
a. Set the AC power switch to OFF.
b. Use a screwdriver to pry the spring away from the yoke (7).
c. Insert a shim (8) and press down until it is flush with the yoke.