So i was using the Roku just fine then a black screen with this message about having to disconnect and reconnect the HDMI cable. After doing so there is now nothing on the screen. Roku has power blank screen. even tried nuking it and the reset did nothing.
There is nothing on the screen at all. The Roku is a 3930x it was a christmas present no near new. The TV is a Magnavox and the connection was working. I have tried both ports on the TV.
The 3930 is the most recent model of the Express, first released in Sep 2019.
Any chance you can test it on a different TV? We want to eliminate each possible trouble point. Watch for both the boot screen (dancing letters) and seeing the Roku home screen after it boots. If it is still dark, try a different HDMI cable. If that doesn't resolve it, then most likely the Express has an electronic issue. A factory reset might restore it, but my guess would be no.
If it's completely dead, you'll have to replace it. Roku has a one year warranty, so if you've had it less than that, you should be able to get it replaced. However, I personally don't recommend the Express. For the additional expense, the Premiere is a much more capable player, supporting 4K/HDR and offering more memory. For a bit more than the Premiere, the Streaming Stick+ has the WiFi Direct remote and better wireless performance.
I wasn't even aware Mangavox still sold TVs, but I see they even offer a few models of Roku TVs. Learn something new every day!
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution." If you appreciate my answer, maybe give me a Kudo.