The MXW70 includes Amplifier Protection Circuitry to detect faults with over temperature, DC offset, and also clipping and power supply faults. If any of these issues are detected the standby LED will blink red.
The standby button can be pressed once to disable the protection indication, and pressed again to power the unit back on once the fault has been resolved.
DC Offset Fault.
This is indicated by a short red blink followed by solid white.
The MXW70 offers loudspeaker protection if the output of the amplifier goes to a high constant voltage (DC) due to an internal fault. This is a rare issue, however, detecting it will protect your loudspeakers from damage.
If this fault occurs then please contact your dealer for servicing, or our support team: http://www.cambridgeaudio.com/contact
Over Temperature.
This is indicated by two short red blinks followed by solid white.
Over temperature can be caused by a combination of high listening levels, low impedance speakers, and poor ventilation. If the amplifier detects this then it will switch itself to fault mode to protect the loudspeakers from damage.
When using lower impedance speakers the amplifier will be working harder and will run at a higher temperature. Eventually if this temperature gets too high it can trigger the protection circuitry.
Similarly if your amplifier is positioned in an enclosed space, or does not have sufficient passive cooling then this can cause issues with overheating.
To solve this issue please leave the amplifier for 5 minutes to cool down before restarting operation, the unit will not power back on if the temperature has not reached a safe level. Please also ensure that the speakers in use have a suitable impedance for the unit.
We would also recommend leaving at least 15cm of space around the amplifier for proper cooling.
Power Supply Fault.
This is indicated by three short red blinks followed by solid white.
This fault is triggered in the unlucky occasion that the power supply develops a fault. This can also be triggered when removing the power while the unit is in use, or following a sudden power outage.
If this fault persists then please contact your dealer for servicing, or our support team: http://www.cambridgeaudio.com/contact
Clipping.
This is indicated by four short red blinks followed by solid white.
The unit will allow output clipping for a very short time, as this may occasionally happen during loud music transients. When this happens a red light will flash quickly, and in the case it is recommended to reduce the volume of the source.
If clipping is persistent then the unit will automatically shut down to prevent damage to the loudspeakers.