James Loudspeaker M1000 - Manual (Page 18)

APPENDIX C – TROUBLESHOOTING
1) THE AMPLIFIER APPEARS TO HAVE NO POWER (NO LEDs COME ON)
There are a few obvious things to check. Make sure the amp is plugged in to an active AC power receptacle
and if it is a switched outlet, make sure the power is turned on. Make sure the rear power switch is turned on.
Once you have confirmed the AC power is turned on, make sure the voltage selector on the rear of the amp is
set correctly. Having the selector at 230V while plugged into an 115V outlet will keep the amp from turning
on.
Check the fuse located in the IEC power receptacle.
2) THE AMPLIFIER WILL NOT COME OUT OF STANDBY MODE
If the amp was configured to use the 12V trigger, if will only turn on when a 12V trigger signal is applied to the
12V trigger input. If you are not using a 12V trigger, then you can reset the 12V trigger to “off” by turning the
amplifier off, and then turning the amplifier on while holding down the left and right front panel navigation
buttons.
The amp could have overheated. Let the amp cool down.
The amp might have suffered an internal component failure. The amplifier will need to be serviced.
3) THE AMPLIFIER IS ON BUT THERE IS NO SOUND FROM THE SUBWOOFER
Check the front panel to see if the green “Signal” indicator is on or flashing. If so, this indicates a signal is
going into the amp. So the problem will be between the speaker output from the amp and the subwoofer,
most likely an open or shorted speaker wire, or a poor connection at either location, or a bad subwoofer.
Make sure the volume is turned up on the amplifier.
If the green signal indicator does not come on or flash, then there is no signal entering the amp and you
should check the cables running into the amp inputs and the source feeding the signal to the amplifier.
If the amplifier is on, but the red standby indicator is on, check the issues listed in item 2.
4) THE AMPLIFIER PRODUCES A BUZZ/HUM IN THE LOUDSPEAKER
Any buzzing or hum that does NOT change level with the volume control is generally caused by a ground loop
condition. This is especially common when the M1000 is located on a different AC line from the other
equipment or when all the electronics are rack mounted so the chassis’s are all grounded via the metal rack.
Though using a ground lift adapter on the amplifier’s AC plug may cure the buzz/hum issue, removing the
ground may result in an unsafe condition if the amp was to experience a power supply failure. We suggest
the use of a ground input isolator such as the Radio Shack “Ground Loop Isolator”, part number 270-054. An
input isolation transformer can also be used.
If the buzz/hum changes with the volume level, it can still be caused by a ground loop and this should be
checked. But also, the buzz/hum could be caused by a bad input cable, so a cable swap is recommended.
5) NO OUTPUT ON THE RCA LOOP THROUGH RCA JACKS
If you are feeding your signal into the XLR inputs, the initial production run of M1000’s did not feed the XLR
outputs to the RCA loop out jacks. So you will need to use the RCA inputs for these models. This applies to
any serial number starting with 0910.
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6) AMP DOES NOT APPEAR TO GET LOUD ENOUGH YET THE CLIP LIGHT IS ON
Check to see if the limiter has been set to a low power level.