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246 TimeHub 5500 User’s Guide
097-55501-01 Revision M – January 2009
Chapter 5 Maintaining the TimeHub 5500
Replacing Fuses
13.Tighten the captive screws at the top and bottom of the card.
Replacing the Fuse in the Output Driver Card
To replace the fuse on the Output Driver card, follow the procedure in this section.
shows the location of the fuse holder on the card.
1. Put on a properly grounded ESD wrist strap.
2. Using a #2 Phillips-head or Pozidrive screwdriver, loosen the captive screws on
the front panel of the card.
3. Remove the card from the shelf.
4. Using a GMT fuse puller, remove the fuse from the fuse holder labeled F1.
5. Replace the fuse with a 1-A GMT fuse. Do not force the fuse when inserting it;
the fuse should easily snap-fit into the holder.
6. Insert the card into the shelf: ensure that the card aligns properly with its mating
backplane connector; push the card into place until it is fully seated into the
backplane connectors.
7. Wait for the Power LED to light, the DS1 and/or CC LEDs to light according to the
output connector cards installed, and the Fail and Alarm LEDs to turn off.
8. Press the Cutoff pushbutton on the Management card several times.
9. Verify that any alarm conditions are cleared.
10.Tighten the captive screws at the top and bottom of the card.
Replacing the Fuse in the EC Card
To replace the fuse on the EC card, follow the procedure in this section.
shows the location of the fuse holder on the card.