Clear-Com PS-704 - Manual (Page 24)

P S - 7 0 4 F O U R - C H A N N E L P O W E R S U P P L Y 3 - 2
TROUBLESHOOTING TIPS
SYMPTOM CAUSE SOLUTION
System does not operate. No
power to the PS-704. Green
power LED is not illuminated
and no short LEDs are
illuminated. No AC power to the PS-704. Check AC connection and cable.
Plug into dependable AC source.
PS-704 has an internal power supply
failure. Unit requires servicing.
Red short LED illuminated. Short or overload on that channel
due to a shorted or miswired cable. Remove cables (one at a time) from
system until the faulty line is located.
Check for shorts between pins #1
and #2. Once the short is removed,
the PS-704 will reset automatically
and the power will come back up
within a few seconds.
Defective remote station. Check remote station and replace if
necessary.
All red short LEDs are
illuminated. System is overloaded. Remove cables (one at a time) from
system to help determine where the
excess current requirements lie.
Re-evaluate system current needs.
Short in multipair cable. Remove cables (one at a time) from
system until the faulty line is located.
Check for shorts between pins #1
and #2.
Hum or buzz in system. Inductive pickup caused by close
proximity of main or remote stations
to power lines or transformers. Relocate offending unit.
10 Ω chassis ground resistor is open. Check the DC resistance for 10 Ω
between the chassis and pin #1 of
any intercom connector.
If this condition occurs, it is because the system ground came into contact with something that was hot
with respect to the power supply earth ground. If this occurs, carefully check the system ground and
AC distribution in the area.
Warning: This is a potentially dangerous situation. A shock hazard may exist between the metal boom of a
remote station headset and ground.
System feedback (acoustical). Volume control at the remote station
is set too high. Adjust.