Solution

This may be an issue related to the settings. 

Please check the RS232 settings when you encounter this issue:

Also, check the RS232 pin definition:

Note: RS232 does not need crossover

If the user cannot use RS232 or Crestron to remotely turn on the power, refer: "Why can't RS232 be used to Power on/off the dvLED Display while in Standby Mode?"