Meyer Sound UPA-1P - Manual (Page 10)

The On/Temp. LED is illuminated but there
is no sound.
1. Verify that the audio source (mixer, EQ, delay) is
sending a valid signal.
2. Make sure the XLR cable is securely fastened to the
XLR audio input connector.
3. Verify that the XLR cable is functioning by substi-
tuting another cable or by using the cable in ques-
tion in a working system.
4. Send the audio signal to another speaker to insure
signal presence and that the level is within the proper
range. Turn the source level down before reconnect-
ing the audio input and increase the level slowly to
avoid a sudden blast of sound.
5. If possible, monitor the audio source with head-
phones.
Hum or noise is produced by the speaker.
1. Disconnect the audio input. If the noise persists, the
problem is within the UPA-P. In this case return the
unit to the factory or nearest authorized service cen-
ter. If the hum ceases, the noise originates some-
where earlier in the signal path.
2. Make sure the XLR cable is securely fastened to the
XLR audio input connector.
3. Send the audio signal to another speaker to insure
signal presence and that the level is within the proper
range. Turn the source level down before reconnect-
ing the audio input and increase the level slowly to
avoid a sudden blast of sound.
5. Hum or noise can be produced by a ground loop.
Since the UPA-P is effectively ground-lifted, the loop
must be broken elsewhere in the system.
The audio produced by the speaker is
distorted or compressed but the limit light
is not illuminated.
1. Make sure the XLR cable is securely fastened to the
XLR audio input connector.
2. Send the audio signal to another speaker to insure
that the level is within the proper range. Turn the
source level down before reconnecting the audio
input and increase the level slowly to avoid a sud-
den blast of sound.
3. Monitor the audio source with headphones.
Polarity within a UPA-P
Use the following test procedure to verify polarity be-
tween drivers in the same loudspeaker:
1. Place a measurement microphone 1 meter from
the front of the loudspeaker at the midway point between
the low and high frequency drivers.
2. Connect a full range signal to the loudspeaker
andnote the frequency response.
The polarity is correct if the frequency response is smooth
through the crossover region (800 Hz to 1.5 kHz). Cancel-
lation of 6dB or more in this region indicates polarity
reversal.
Troubleshooting
This section suggests several possible solutions to some
common problems encountered by UPA-P users and is
not intended to be a thorough troubleshooting guide.
Qualified electronics technicians with access to a test
bench can request the following documents from Meyer
Sound: Troubleshooting Guide, The Low Frequency Driver
Replacement Procedure,
and The High Frequency Driver Re-
placement Procedure for the UPA-1P/2P.
The On/Temp. LED does not illuminate, there
is no audio, and the power supply fan is
off.
1. Make sure the AC power cable is the correct type for
the regional voltage and that it is securely connected
to the AC inlet then unplug and reconnect the AC
cable.
2. Use an AC voltmeter to verify that the AC voltage is
within the ranges 88–264V, 47–63 Hz.
3. Call Meyer Sound Technical Support.