Trouble Shooting - JBL EON 612 User Manual

TROUBLE SHOOTING

Symptom
No sound
No sound, speaker is connected
to working AC power but won't
come on.
No sound. Speaker comes on.
No sound with microphone
connected directly to the
MIC/ LINE input.
Signal sounds distorted and
very loud, PEAK light is lit
most of the time.
Signal sounds distorted even at
moderate volumes, LIMIT light
is not lit.
Lots of hiss in the sound,
the mixer controls are at
very low settings.
Noise or hiss heard at output.
Hum or Buzz that increases or
decreases when the mixer level
controls are moved.
Hum or Buzz
22
Likely Cause
Speaker not connected
to active AC power
Power not switched on
Speaker power cable is faulty
or improperly connected.
Signal source
(mixer, instrument, etc.)
is not sending.
Faulty cables and
connections
Microphone requires
phantom power
Excessive input signal, trying
to exceed the capabilities of
the speakers
Mixer or other source
is overdriven
Improper gain structure
Noisy source device
Improper A/C ground or
faulty equipment connected
to mixer input
Faulty cable between source
equipment and mixer
Improper A/C grounding,
ground loops
Excessively long
unbalanced cable run
Improper system gain
structure
What to do
Verify that speaker is connected and that the circuit is on
Switch on power and verify that power LED is on
• Re-seat the power cable at both ends.
• Substitute a known-good power cable
• Check VU meters on the source mixer
• Verify that the tape or CD is playing.
• Use headphones to verify that the instrument is actually
sending an audio signal
• Disconnect and re-seat signal cables.
• Replace suspected cable with a known-good cable
The EON does not supply phantom power. Switch to a dynamic
microphone, use a battery powered microphone (if possible),
use an external phantom power supply for condenser type microphones.
• Reduce the output level of the source.
• Turn down the level controls on the speaker.
• Use additional EON speakers.
Review the Owner's Manual for your mixer and adjust controls as needed.
• Input sensitivity (gain)
• Channel faders
• Master faders Once this is done, review the instructions in the Quick
Start section of this guide.
• Make sure that the MIC/LINE switch is in the LINE (disengaged) position.
• Reduce the level settings at speaker. Review the Owner's Manual for
your mixer and adjust controls as needed.
• Input sensitivity (gain)
• Channel faders
• Master faders
Disconnect the devices that are connected to your speaker one at a time.
If the noise goes away, the problem is with the source or the
connecting cable.
Disconnect or mute channels one at a time to isolate the problem. Refer to
the owner's manual of the faulty equipment for troubleshooting help.
Substitute a known-good cable for the suspected faulty cable.
• 'Lift' the audio ground by using an XLR/F to XLR/M adapter on one end.
• Re-route audio cables away from AC power and lighting cables.
• Use the balanced outputs (if available) of your mixer or source
equipment to drive your EON speakers.
• Use a "DI" (direct injection) box to convert your unbalanced equipment
output to a balanced output.
Reduce the INPUT level controls and increase the output level of your
source devices.