M S - 7 0 2 T W O - C H A N N E L M A I N S T A T I O N
3 - 2
TROUBLESHOOTING TIPS
SYMPTOM
CAUSE
SOLUTION
System does not operate. Blue
talk
buttons
do not illuminate
and
short
lights do not
illuminate.
No AC power to the MS-702.
Make sure the power switch on the
rear panel is turned
on
. Check the AC
connection and cable. Plug into a
dependable AC source.
The MS-702 has an internal power
supply failure.
Unit requires servicing.
System does not operate when
power switch is turned on. Blue
talk
lights and red
short
lights
wink.
Direct short on the intercom channel
indicated by the red
short
light.
Remove the intercom line cables one
at a time from that channel until the
faulty line is located. Once the short is
removed, the MS-702 will reset
automatically and power will come
back up. Check for shorts between
pins #1 and #2 or improper cable
wiring.
Red
short
light is illuminated.
Short or overload on that channel due
to a shorted or miswired cable.
Remove the intercom line cables one
at a time from the system until the
faulty line is located. (The red
short
light will then turn off.) Check for
shorts between pins #1 and #2 or
improper cable wiring. Once the short
is removed, the MS-702 will reset
automatically and power will come
back up.
Defective remote station.
Check the remote station and replace
if necessary.
Both red
short
lights are
illuminated.
System is overloaded.
Remove the intercom line cables one
at a time from the system to help
determine where the excess current
requirements lie. Re-evaluate the
system current needs.
Short in multipair cable.
Remove the intercom line cables one
at a time from system until the faulty
line is located. Check for shorts
between pins #1 and #2 or improper
cable wiring.
Problem: Hum or buzz in
system.
Inductive pickup caused by close
proximity of this main station or
connected remote stations to power
lines or transformers.
Relocate the offending unit.
