AT&T 3.0 manual Power Supply Problems, Checking the Power Supply, Checking the LED

Power Supply Problems

■Save the system programming to a memory card (beginning with Release 3.0). See Appendix D, “Backing up with a Memory Card, ” for detailed instructions. If automatic backups are performed, it may not be necessary to save system programming.

NOTE:

If the processor module is not functioning, it may not be possible to back up system programming.

Power Supply Problems

If the power supply fails, all components connected to the carrier are automatically shut down.

Checking the Power Supply

If you suspect power supply failure, check the following:

■Power supply LED

■Interlocking post (on the carrier, behind the power supply)

■Ring generator, if present

■Auxiliary power unit(s), if present

WARNING:

Never remove the power supply without first turning off the power switch and disconnecting the power cord from the AC outlet.

Use the following procedures to check the power supply.

Checking the LED

If the power supply’s LED is off, check the power switch. If it is off, turn on the power switch for each power supply in the control unit. Start with the rightmost carrier and end with the basic carrier. Watch for the following responses:

4-2Control Unit Problems