The MXW70 includes Amplifier Protection Circuitry to detect faults with Over Temperature, DC offset, Clipping and Power supply fault. If any of these faults are detected the button LED will blink red.
Press the button once to disable the protection indication, and press again to turn unit back on, when the fault has been removed.
DC
This is indicated by 1 short red blink followed by solid white.
MXW70 offers loudspeaker protection if the output of the amplifier goes to a high constant voltage (DC) because of some internal fault. This is a rare fault, although detecting it will protect your loudspeakers from damage.
If this fault occurs, please contact your dealer for service or our support team https://www.cambridgeaudio.com/contact
Over Temperature
This is indicated by 2 short red blinks followed by solid white
Over temperature can be caused by a combination of high listening levels, low impedance speakers and insufficient ventilation. If the internal temperature reaches a high level, the amplifier will automatically switch into a fault mode to protect itself from damage.
If the loudspeaker impedance is low, the temperature of the amplifier may rise faster as the amplifier is working harder.
If the amplifier is mounted in a closed cabinet, the over temperature detection may activate/reactivate after a short listening time.
Leave the unit for 5 minutes to cool down before resuming normal operation. Check if the loudspeaker impedance is suitable for the selected MXW70 operation mode, and also make sure there’s at least 15cm room all around the unit to allow the necessary convection cooling.
The unit will not resume operation even when pressing the standby button if the internal temperature hasn’t reached a safe level yet.
Power Supply Fault
This is indicated by 3 short red blinks followed by solid white.
In the unlucky event that the internal power supply becomes faulty. this can also happen when removing the power cord whilst unit is on, or if there’s a sudden power outage.
If the issue persists, please contact your dealer for service or our support team https://www.cambridgeaudio.com/contact
Clipping
This is indicated by 4 short red blinks followed by solid white.
The unit will allow output clipping for a very short time, as this might occasionally happen during loud music transients. Red light will flash quickly. In this case it is recommended to reduce the volume of the source.
If clipping condition is persistent, then the unit will automatically shutdown to prevent loudspeaker damage.