Magnetic Pickup Phasing Adjustment - Printronix p300 Maintenance Manual

5–12. Magnetic Pickup Phasing Adjustment (Figure 5–9)
NOTE: Unless otherwise directed by this manual, perform gap adjustment,
paragraph 5–11 before proceeding.
1. Loosen screw (6) until MPU arm (7) can be pivoted, but only with some effort.
2. Load printer with 14 7/8–inch wide single–part paper.
NOTE: If exerciser is not available, use self–test Es or host computer to gener-
ate all Hs. Wide paper is required if using self–test.
3. Connect exerciser to printer interface connector (8).
NOTE: Exerciser will interface only with parallel Centronics or Dataproducts
connectors.
4. Set exerciser controls as follows.
LINE LENGTH = 132
CHARACTER = H
SPECIAL = None
FUNCTION = LF
POLARITY = Low True if jumper W7 is installed on Logic A PCBA. High True if jumper W7
is not installed on Logic A PCBA.
5. Press ON LINE switch and observe printout. The relative horizontal position of dots in alternate
rows should be as shown below. If either incorrect condition is observed, position the MPU arm
until the dots in succeeding rows are aligned horizontally to within 0.005 inch.
ALIGNMENT
NOTE: To precisely set MPU phase, a long shanked screwdriver or Allen
wrench shaft may be used as a pry bar with the bracket arms as a fulcrum.
6. Tighten screw (6). Repeat printout and readjust as necessary.
7. Install covers per paragraph 5–18b.
8. Return printer to normal operation by performing steps 10 through 13 of paragraph 5–17b.
5–22
NEEDS CORRECT NEEDS
ALIGNMENT
P300/P600 Corrective Maintenance