If I have this correct your pump is running in the tank but the controller screen is black, not displaying any settings or speeds.
Have you touched the center dial or other buttons to wake the controller up from its ''sleep mode'' ?
You can also try and power cycle the unit by unplugging from wall outlet power, waiting a few seconds and plugging the unit back in.
Please let me know if you need further support and please try to be more descriptive and clear on your issue so I understand correctly.
Thanks.