Trouble Shooting - Alto ELVIS 12 MKII Service Manual

8. Trouble shooting

Symptom
Speaker not connected to active AC power
No sound
Power not switched on
No sound, speaker is Speaker power cable is faulty or omproperly
connected to working AC connected.
power but won't come on
Blown fuse
Signal source(mixer, instrument, etc) is not
sending
No sound. Speaker cones on
Faulty cables and connections
No sound with microphone
connected directly to the Microphone requires phantom power
MIC/LINE input
Signal sounds distorted and
Excessive input signal, rying to exceed the
very loud, LIMIT light is lit
capabilities of the speakers
most of the time
Signal sounds distorted
even at moderate vlumes, Mixer or other source is overdriven
LIMIT light is nong lit
Lots of hisee in the sound,
the mixer controls are at very Inproper gain structure
low settings.
Noise or hiss heard at output Noisy source device
Improper A/C ground or faulty equipment
Hum ot Buzz that increases
connected to mixer input
or decreases when the mixer
level controls are moved. Faulty cable between source equipment and
mixer
Improper A/Cgounding, ground loops
Hum or Buzz
Excessively long unbalanced cable run
Improper system gain structure
The inputs from INPUT 1 and
INPUT 2 aren't coming out of MIX/LOOP SWITCH set improperly
the OUT connector
The speaker connected to
the OUT connector goes up
involume when I adjust the MIX/LOOP SWITCH set improperly
INPUT 3 control on the first
speaker
Microphone are pointed into the speakers
Speakers feed back and howl
Equializer settings are incorrect
when the micronphone
volume is truned up
Excessive gain
Likely Cause
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Verify that speaker is connected and that the circuit is on
Switch on power and verify that power Led is on
*Re-seat theh power cable at both ends;
*Substitute a known-good power cable
*Check fuse and replace with same type "spare fuse in holder"
*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 and
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 yout 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
yout mixer and adjust controls as needed;
*Input sensitivity(gain);
*Channel faders;
*Master faders;
Disconnect the devices that are connected to yout speaker one at a time.
If the noise goes away, the problem is with the source or the connecting
cable.
Disconnect or mute channels on at a time to isolate the problem. Refer to
the owner's manual of the faulty equipment for trouble shooting 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 yout 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.
Set the MIX/LOOP SWITCH to the MIX position(depressed)
Disengage the MIX/LOOP OUT switch, set to LOOP.
Move thespeakers so they do not point at the microphone's pickup
pattern.
Locate the feedback frequency and reduce it using the mixer EQ or an
external equalizer.
Reduce the gain at the mixer and move the micronphone closer to the
sound source.
What to do