Q: MAX7313 : How to turn off an LED?
A : To turn an LED off, the phase 0 register bit associated with that port would have to be set to 1 so that the PWM intensity setting can be configured to high impedance state by setting it to 0xF. It is not possible to turn off the LED if this phase 0 register bit were set to 0. More information can be found on Tables 8, 11 and 12 of the datasheet.