Carriage Support Shaft - IBM 4247 Maintenance Information

Adjustment
1. Remove the printer covers. See "Printer Covers" on page 347.
2. Loosen the lock nut and adjust the screw until a force of 0.85 to 0.95 kg (1.9 - 2.1 lb) is required to push the
upper half of the belt (center between the printhead and the left side frame) to touch the bottom half of the
belt.
3. Tighten the lock nut and check the adjustment again.
4. Repeat steps 2 and 3, as needed. Incorrect belt tension contributes to '56/056' errors (also seen as margin
shifts and printhead slams).

Carriage Support Shaft

Service Check and Adjustment
1. Remove all paper, the ribbon cartridge, and the paper bail assembly.
2. Loosen the right side support shaft screw.
3. Measure the gap between the printhead and the platen at both ends of the platen, right and left.
The correct gap is 0.25 to 0.30 mm (0.010 to 0.012 in.) when the AFTA indicator is pointed at 1.
The correct difference in the gap between the left and right ends is 0.08 mm (0.003 in.).
4. Using pliers, rotate the eccentric bushing until a minimum difference between the left and right end gaps is
obtained. See Figure 52 on page 281.
5. While holding the eccentric bushing with pliers to prevent it from moving, firmly tighten the right side support
shaft screw.
Chapter 5. Removals and Adjustments
280