IBM 6400 Maintenance Information Manual page 201

Installation
The hammer bank contains a strong magnet. To prevent damage to the
hammer tips, do not let the hammer bank cover assembly snap into
place as the hammer bank magnet attracts it. Any impact of the cover
against the hammer bank can break hammer tips.
1. Early models:
a. With the thick plate facing the hammer bank, engage the bottom edge
of the hammer bank cover assembly on the alignment pins. Engage
the round hole first, then the oblong hole, to ensure that the cover lies
flat on the hammer bank.
b. Gently lower the hammer bank cover assembly until it lies flush on
the hammer bank.
c. Check that the hammer bank cover assembly is properly positioned
over the alignment pins and hammer tips.
2. Later models:
a. Position the hammer bank cover on the alignment pins on the
hammer bank. Make sure the hammer bank cover is properly
positioned over the alignment pins and hammer tips and lies flat on
the hammer bank.
b. Install all 12 hold-down screws finger tight. Using a Torx T-10 driver,
torque the 12 hold-screws to 14 inch-pounds (1.58 N•m) in the
sequence shown in Figure 32 on page 202.
c. With the seam of the folded lower edge of the ribbon mask facing
inward (toward the hammer bank cover), position the ribbon mask on
the alignment pins on the hammer bank cover. The ribbon mask is
correctly installed when the angled ends of the ribbon mask match
the angled ends of the hammer bank cover. Install the three clamp
plates and six screws finger tight. Using a Torx T-10 driver, torque the
six screws to 14 inch-pounds (1.58 N•m) in the sequence shown in
Figure 32 on page 202.
3. Install the shuttle frame assembly (page 242).
4. Return the printer to normal operation (page 153).
Cover Assembly, Hammer Bank / Ribbon Mask
ATTENTION
201