ET-LINC Classroom
Trouble-Shooting Check List
PROBLEM: No Audio from distant classroom.
  • Ensure that the system is on: Control panel system power button lit, and that the Amplifier power lamp is lit.
  • The first three knobs (from left) on the power amp are the audio return signals from the distant classrooms. These knobs should be at 12 o'clock for each corresponding classroom which is on line.
  • Echo canceller lamps should show 4 wire mode with "OK" flashing. Privacy lamp should not be lit.
PROBLEM: Squealing noise, or feedback coming from speakers.
  • Make sure that the VCR PLAY button on the control panel is not lit. If no tape is in the VCR and the play mode is selected, then feedback will result.
  • AFTER checking above, each classroom should "train" their system by pressing both the volume up and volume down buttons simultaneously. This will cause a hissing sound which will last for several seconds. EACH classroom, in turn, should do this - BUT NOT AT THE SAME TIME.
PROBLEM: System power is OFF, but my video monitors are ON.
It is possible for the video monitors to become "out of sync" with the system due to power failures, power glitches, or thunderstorms. To rectify, you must - with the system power button off - manually turn all the monitors off via the power buttons on the video monitors. Now, when you turn your system back ON, your monitors will be back "in sync". with the system.
PROBLEM: System is not responding to commands from my control panel.
Although rare, it is possible - particularly after a thunderstorm or power glitch - for the control system to become "latched up". The control system is a computer, and like all computers must be "re-booted" on occasion.

To do this:

  1. If possible turn off your system
  2. Turn OFF the UPS power switch for 30 seconds (UPS is located under the center of the console) .
  3. Turn the power switch on the UPS back to ON and allow 30 seconds for the system to re-boot and initialize prior to trying to use it.
SPECIAL AUDIO NOTE:
If you are on line with more than one classroom, and another classroom can not hear audio from your room, BUT one or more classrooms CAN hear your audio then THE PROBLEM IS NOT IN YOUR ROOM! DO NOT ADJUST YOUR SYSTEM as the problem is elsewhere.
There is only one transmit line from your room going to the network; if anyone can hear you then your transmission is proper.