Work through these checks
Replace the remote batteries
A stick that is on but not responding looks exactly like one that won’t start. Fit new AAA alkaline batteries. If the TV shows the Fire TV home screen, the stick was on all along: see Firestick remote not working.
Use the original power adapter, in the wall
Use the cable and adapter that came with the stick, plugged into a wall socket. Amazon advises against the TV’s USB port, and if you’ve lost the originals, it recommends Amazon-branded replacements. Other chargers and TV USB ports may not supply enough power.
Power cycle it
Unplug the power from the stick or the wall for several seconds, then plug it back in. Try a different wall socket too.
Check the input and cable
Press the source or input button on the TV remote and pick the HDMI port the stick uses. Plug the stick straight into the TV, not through an HDMI hub, and use a high-speed HDMI cable if you use an extension.
Force a restart if the screen is frozen
If you see a picture but nothing responds, hold Select and Play/Pause together for about five seconds. If that fails, unplug the power, wait 60 seconds and plug it back in.
It starts but gets stuck
If you see the Fire TV logo and it goes no further, see Firestick stuck on the logo. If the screen is black, see Firestick black screen.
When to replace it
If the stick shows nothing on two different TVs, with the original adapter in a working wall socket, it has probably failed. Check Amazon’s device support for warranty options before buying a new one, and see Fire TV models for IPTV if you do.