IBM 6500-V1P Maintenance Manual - Page 189

General Symptom List Table 5. General Symptom List Symptom Corrective Action Stacker chatters at upper or lower limit 1. Power off and unplug the printer. Unload paper. 2. Open the rear cabinet door, press the elevator disable switch and manually move the elevator up and down, through its entire range of motion. Check that elevator motion is not blocked or hindered by the operator panel cable or other obstruction. The elevator mechanism is sensitive to binding and obstructions, so do all adjustments and servicing very carefully. Remove any obstructions or reroute the stacker operator panel cable as necessary. Check the following areas for possible binding: a) Cables adjacent to the elevator and vertical rails. b) Make sure the paper tent is positioned correctly. c) Make sure the paper fences in the elevator slide freely. d) Check for obstructions near the upper and lower limit switches. 3. Verify that the stacker rails are vertical and parallel. Adjust the stacker rails if necessary: they must be vertical and parallel. 4. Make sure the elevator is parallel to the printer. 5. Plug in the printer and power it on. Operate the power stacker. While the stacker is operating, check that: a) all motors are operating b) the paddles are rotating c) the elevator moves smoothly and without obstruction d) the timing belts are undamaged and the belt pulleys are not slipping e) the extension springs are attached and undamaged (not bent or stretched) f) the drive rollers are not damaged g) the constant force springs are tightly mounted and undamaged Tighten pulley setscrews and/or replace damaged components as necessary. 6. While the stacker is operating, observe if assisting the motion of the elevator helps prevent chattering. If so, binding is suspected. Inspect the vertical rails for foreign material (grease, dirt, adhesive residue, etc.) that might cause binding. Clean the rails if necessary. Check that the elevator pulleys (item 12, Figure 92) are not mounted so tightly to the vertical rails that they can cause binding. From 0.005 to 0.020 inches of clearance between the pulleys and the vertical rails is desirable. 189