Lectrosonics MM400b - Manual (Page 17)

Watertight Miniature UHF Belt-Pack Transmitter
Troubleshooting
Before going through the following chart, be sure that you have a good battery in the transmitter. It is important that
you follow these steps in the sequence listed.
SYMPTOM
TRANSMITTER PWR LED OFF
NO TRANSMITTER MODULATION LEDs
-10 MODULATION LED IS BLINKING
GREEN AND RECEIVER HAS NO AUDIO
RECEIVER INDICATES NO RF
NO SOUND (OR LOW SOUND LEVEL),
RECEIVER INDICATES PROPER AUDIO
MODULATION
DISTORTED SOUND
HISS AND NOISE -- AUDIBLE DROPOUTS
EXCESSIVE FEEDBACK
POSSIBLE CAUSE
1) Battery is inserted backwards.
2) Battery is dead.
3) Power ON/OFF switch configured to Normal Mode and is
set to OFF.
1) Verify Transmitter PWR LED is glowing.
2) Gain control turned all the way down.
3) Mic capsule is damaged or malfunctioning.
4) Mic cable damaged or mis-wired.
1) Power ON/OFF Switch is configured for Audio Mute Mode and
the switch is in the OFF, or mute position. (See Controls and
Functions.)
1) Transmitter not turned on.
2) Transmitter battery is dead.
3) Transmitter antenna missing or defective.
4) Receiver antenna missing or improperly positioned.
5) Transmitter and receiver not on same frequency.
Check switches/display on transmitter and receiver.
6) Operating range is too great.
1) Receiver output level set too low.
2) Receiver output is disconnected; cable is defective or connectors
not wired correctly.
3) Sound system or recorder input is turned down.
4) Receiver/Transmitter compatibility mode mismatched.
5) Transmitter audio muted.
1) Transmitter gain (audio level) is far too high. Check Modulation
LEDs on transmitter and receiver as it is being used. (See
Operating Instructions, Attaching a Microphone and Adjusting
Audio Levels.)
2) Receiver output may be mismatched with the sound system or
recorder input. Adjust output level on receiver to the correct level
for the recorder, mixer or sound system.
3) Excessive wind noise or breath “pops.” Reposition microphone
and/or use a larger windscreen.
4) Transmitter is not set to same frequency as receiver. Check that
frequency select switches on receiver and transmitter match.
5) Receiver/Transmitter compatibility mode mismatched.
1) Transmitter gain (audio level) far too low.
2) Receiver antenna missing or obstructed.
3) Transmitter antenna missing.
4) Operating range too great. Check RF level on receiver indicator.
1) Transmitter gain (audio level) too high. Check gain adjustment
and/or reduce receiver output level.
2) Transmitter too close to speaker system.
3) Mic is too far from user’s mouth.
Rio Rancho, NM 17