Please try out the following steps for resolution -
a. Try to select the input source as HDMI on your Television.
b. Try to plug in the device in a different HDMI port.
c. Try to plug in the device with or without the HDMI extension cable.
d. Try to use a different power source like a mobile charger.
e. In case none of these help, your device might be faulty. Please contact support to ask for a replacement in case you are still under the warranty period.