Nortel Meridian 1 Manual page 97

Possible cause
Defective MDU
(lit LED)
Defective cable
between MDU and
MSI or EMSI card
Clearing common equipment faults
Action
Unseat the MDU and the MSI or EMSI card, then reinstall them. Make
sure the cable between the MDU and MSI/EMSI is securely connected.
(In a dual CPU system, check both MSI/EMSI cards.) If the MDU does not
recover, continue with this procedure.
Try to restore the hard drive from disks:
— Hardware disable the MSI/EMSI (in a dual CPU system, disable both
MSI/EMSI cards), remove the card, and set SW4 to OFF.
— Reinstall the MSI/EMSI card and hardware enable it.
— Try to software enable the MSI/EMSI card through the Overlay
Loader (you will not be in an overlay) by entering:
****
ENLT
If you cannot load the program, try to enter LD 37 through the
maintenance telephone:
— If you can load the program, test the port for the system terminal you
were using.
— If the port is okay, test the cable to the system terminal.
— If the cable is okay, check the system terminal.
If you cannot load a program through the system terminal or the
maintenance telephone, replace the MDU.
If the MDU is still faulty, go to the next possible cause.
Replace the cable to each MSI or EMSI card.
Try to test the MSI/EMSI and MDU by entering:
LD 37
MSI x "x" represents the MSI/EMSI card number 0 or 1.
If the MDU is still faulty, go to the next possible cause.
(continued)
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Meridian 1 Fault clearing