Comdial DX-80 Technical Manual page 72

Maintenance and Trouble Shooting
Symptom(s)
(Continued)
No system CPU Heartbeat
operation. LED Dark or
Lit steady
72
Diagnostic Cause(s)
Aid
Memory strap
in "Cold Start"
position
Power Switch
AC Fuse
DC Fuse
SPI Buss Error
Comdial
Action
If the memory strap is in the "Cold Start"
position, initialize the system as described in
Section 2.18, Power-up Initialization (Cold
Start).
Switch the KSU AC power switch on the "ON"
position.
Switch KSU power to the OFF position and
remove cover (four screws). Locate the system
power supply in the upper left corner of the
KSU interior and inspect the AC fuse for
continuity (DVM required).
Switch KSU power to the OFF position and
remove cover (four screws). Locate the system
power supply in the upper left corner of the
KSU interior and inspect the AC fuse for
continuity (DVM required).
Switch KSU power to the OFF position and
remove cover (four screws). Then check for
the following:
1. Locate each expansion module and verify
the ribbon cable connection is accurate and
secure.
2. Check for improper aligning of module
connectors.
3. Detach all station cabling and retest.
4. Check all socketed IC's for good "seated"
connections.
5. Unplug one module at a time and retest until
failed component is found.
6. Perform Initialization and Power Up
sequence. Note: this is an emergency action
since the unique customer database will be
erased and the system will reboot with default
database programming.
7. If this does not clear the trouble, replace
KSU1 and initialize it as described in Section
2.18, Power-up Initialization (Cold Start).
October, '03