STARPLUS Starplus DHS-L, Technical Manual, Page: 258 / 294

6-4 System D iagnosti cs
Chapter 6 - Maintenance/Troubleshooting
System Diagnostics
Table 6-1: Central Processor Unit (CPU)
Symptom Diagnostic Aid Cause Corrective Action
No system operation
LCD telephones have
no display
No LED’s lit at any
telephones
Power Supply LED
Heartbeat/LED not
flashing
No AC input Check commercial AC outlet.
KSU Power
Cord Verify that both ends of AC cord are plugged in.
Power On
Switch Switch the KSU AC power switch to the ON
position.
AC Fuse Inspect and replace PS exterior AC input fuse.
DC Fuse Inspect and replace PS DC output fuse.
No system operation
LCD telephones may
have data frozen on
displays
No LED’s lit at any
telephones or
intermittent
CPU is locked up
CPU
Heartbeat/LED not
flashing
Initialization
Switch
1. Verify initialization switch is in ON position.
† Power down, remove MPB Module, and
install MPB.
† If the Initialization switch is not in the ON
position when the KSU is powered, the
Power Up Initialization sequence at the
end of
Chapters 2 & 3 should be followed.
† If the system was properly initialized,
proceed to Step 2.
2. Power up and observe system recovery. ( The
system power should rem ain off for a least 5
seconds for this test).
If no heartbeat is seen
proceed to Step 3.
3. Power down, detach all station cabling, and
power up. (The system powershould remain off
for a least 5 seconds for this test). If no
heartbeat is seen proceed to step 4.
4. Power down, inspect for the following:
† Loose or unplugged Modules or cables.
† Improperly aligned ribbon cables.
† Improper installation of the system
software EPROM, located in socke t U9
CPU M odule.
EMERGENCY ACTION
Since the unique battery protected
customer database will be erased
and the system will boot up with
default programming.
1. Move initialization switch to the OFF position.
2. Return initialization switch to the ON position.
3. IF CPU/LED is still not flashing, replace MPB.
4. Initialize and test according to the Power Up
Initialization sequence.