Hologic DISCOVERY A, Technical Manual

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Discovery QDR Series Technical Manual
5-3
1. Move the C-arm to the center of the table.
2. Shut down the computer and then turn off the main circuit breaker on the foot end
pedestal.
3. At the encoder end of the belt, loosen the 2 bolts holding the tension block,
remove the tensioning nut, and remove and replace the belt.
4. Install the tension spring and tensioning nut.
5. Tighten the tension nut so that the spring compresses to 7/8 inch. The bracket cut-
out can be used as a measuring guide (the inside of the washer should be flush
with the bracket cut).
6. Tighten the two mounting bolts holding the tension block.
7. Restore power, boot the computer and login as Service.
8. Perform the procedure in “MOTOR$AY” on page 3-35.
5.2.2 C-Arm Y Motor or Gearcase
To remove and replace the C-arm Y-Motor or Gearcase, refer to Figure 5-1 and follow the
procedure below:
1. Move the C-arm to the center of the table.
2. Shut down the computer and then turn off the main circuit breaker on the foot end
pedestal.
3. At the encoder end of the belt, loosen the 2 bolts holding the tension block,
remove the tensioning nut and remove the belt.
4. At the motor end of the belt, remove the cable cover and unplug the motor cable
from the Motor Controller Board.
5. Remove the four Allen bolts, and nuts, holding the motor and gearcase.
Note: The two bottom nuts are accessible with a ratchet wrench and extension.
6. Remove the motor first, then the gearcase.
7. If replacing the gearcase, install the pulley from the old gearcase on the new
gearcase.
8. Replace the motor and gear case assembly making sure to align the gasket cor-
rectly. Snug the Allen bolts, but do not over tighten.
9. Install the belt on both pulleys.
10. At the encoder end of the belt, install the tension spring and tensioning nut.
11. Tighten the tension nut so that the spring compresses to 7/8 inch. The bracket cut-
out can be used as a measuring guide (the inside of the washer should be flush
with the bracket cut).
12. Tighten the two mounting bolts holding the tension block.