3–8
DECbridge 500/600 Problem Solving
To replace a logic module, refer to Figure 3–3 and follow these steps:
1. Verify that the replacement module is at the same revision or a higher revi-
sion than the failed module.
2. If an AP/AP2 module is being replaced:
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Make sure the switches on the replacement AP module are set to the same
positions as the switches on the removed AP module.
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Since the AP module contains the address ROM(s) for the bridge, the
physical address of the bridge changes when the AP module is replaced.
An address label on the module lists the new address.
3. Remove ac power to the bridge, disconnect all interface cables, and attach
the ESD ground strap to your wrist and to the bridge (Section 3.2).
4. Check that the logic module ejector levers are in the unlock position (swung
outward). Hold the replacement module component-side up and carefully
slide it into the appropriate card cage slot until it makes contact with the
backplane connector. Do not let the components on the bottom of the module
scrape against the ejector levers of the module below it.
5. Firmly push the ejector levers inward until the module is fully seated into the
connector. (Note: When all modules are properly inserted, all the ejector le-
vers should be aligned.)
6. Using the Phillips-head screwdriver, tighten the two quarter-turn fasteners
that attach the module to the card cage (by pushing in and turning the screw-
driver clockwise).
7. Connect the interface cables, then the power cord (Section 3.2).
8. Wait for self-test to complete and check the state of the LEDs to ensure that
the unit is operational (Section 2.2).
