HP LaserJet Enterprise 500 Maintenance Manual - Page 110

Platen Gap Adjustment

Page 110 highlights

Chapter 5 Platen Gap Adjustment Platen Gap Adjustment Note Only do this procedure if the original equipment shuttle frame assembly or platen has been replaced by a new or refurbished unit or if you have been instructed to do so in a troubleshooting procedure. Caution 1. Prepare the printer for maintenance (page 100). 2. Remove the shuttle cover assembly (page 141). 3. Loosen the platen open belt (page 104, steps 2, 3, and 4). 4. Raise the forms thickness lever (1) to the fully open position. Do not force the platen against the feeler gauge and do not move the feeler gauge laterally across the hammer bank. Damage to the hammer tips will result. Caution 5. Insert a 0.011 inch (0.28 mm) flat feeler gauge (2) straight down between the hammer bank cover plate (3) and ribbon mask (4), within four hammer positions of the left end of the hammer bank. Adjust the platen set screws less than 1/4 turn on one side, then check the other side. Adjustment sensitivity is approximately 0.03 inch per revolution of the set screw. Also, insert the feeler gauge no more than 2 inches down from the top of the ribbon mask. 6. Gently close the forms thickness lever (1). As the platen is closing, gently slide the feeler gauge up and down, keeping it between the hammer tip and ribbon mask. If the feel is too tight when the platen is being closed, adjust the 3/32 inch set screw (5) at the end of the platen counterclockwise. If the feel is too loose, adjust the set screw clockwise. With the forms thickness lever closed all the way, the feeler gauge should contact both the tips and the ribbon mask and move with light friction. Shift the gauge slightly to verify. 7. Repeat steps 4 through 6 at the right end of the hammer bank. 8. After adjusting both sides, check the gap again at both ends. Readjust if necessary. 9. When the platen gap is correct at both ends of the platen, adjust the platen open belt (page 104). 10. Install the shuttle cover assembly (page 141). 11. Check the hammer phasing adjustment (page 121). 12. Return the printer to normal operation (page 101). 110

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110
Chapter
5
Platen Gap Adjustment
Platen Gap Adjustment
1.
Prepare the printer for maintenance (page 100).
2.
Remove the shuttle cover assembly (page 141).
3.
Loosen the platen open belt (page 104, steps 2, 3, and 4).
4.
Raise the forms thickness lever (1) to the fully open position.
5.
Insert a 0.011 inch (0.28 mm) flat feeler gauge (2) straight down between
the hammer bank cover plate (3) and ribbon mask (4), within four hammer
positions of the left end of the hammer bank.
6.
Gently close the forms thickness lever (1). As the platen is closing, gently
slide the feeler gauge up and down, keeping it between the hammer tip
and ribbon mask. If the feel is too tight when the platen is being closed,
adjust the 3/32 inch set screw (5) at the end of the platen
counterclockwise. If the feel is too loose, adjust the set screw clockwise.
With the forms thickness lever closed all the way, the feeler gauge should
contact both the tips and the ribbon mask and move with light friction.
Shift the gauge slightly to verify.
7.
Repeat steps 4 through 6 at the right end of the hammer bank.
8.
After adjusting both sides, check the gap again at both ends. Readjust if
necessary.
9.
When the platen gap is correct at both ends of the platen, adjust the
platen open belt (page 104).
10.
Install the shuttle cover assembly (page 141).
11.
Check the hammer phasing adjustment (page 121).
12.
Return the printer to normal operation (page 101).
Only do this procedure if the original equipment shuttle frame assembly or
platen has been replaced by a new or refurbished unit or if you have been
instructed to do so in a troubleshooting procedure.
Note
Do not force the platen against the feeler gauge and do not move the
feeler gauge laterally across the hammer bank. Damage to the hammer
tips will result.
Caution
Adjust the platen set screws less than 1/4 turn on one side, then check the
other side. Adjustment sensitivity is approximately 0.03 inch per revolution
of the set screw. Also, insert the feeler gauge no more than 2 inches down
from the top of the ribbon mask.
Caution