If you have a Director amplifier series D4600, D2800 or matrix series M6400 or M6800 and you notice that the bottom LED of each LED ladder is blinking ready, do not be alarmed.
THIS IS NORMAL
The red LED is a status light, or “heartbeat” LED. Each red blink indicates the amp is being scanned by the internal DSP to confirm all is well on each zone.
The blinking red LED means all is good.
You should only get worried if that bottom LED becomes SOLID red, then that indicates there is a short on that particular zone.