I seem to be having the same issue on my Roku Ultra. It was fine this morning and at lunch it powers on to the TV searching for signal. I unplugged the Ultra for a few minutes and during the "Roku" boot up the TV can see it but then it just goes back to searching for signal. Tried everything mentioned in this thread except trying to factory reset the Ultra. Using that as a last resort.
We'd like to take a closer look to see if there's anything else we can suggest to help. How are you powering the device? Is it plugged into the TV USB port, or is it plugged into a wall outlet with the provided cables? In addition, have you tried using another HDMI port on your TV as well as trying your device on another TV to see if you are seeing the same issue with no signal?
With more information, we will be able to assist you further.
I am powering it with the supplied power cable plugged into the wall outlet. I have tried other TV HDMI ports as well as other HDMI cables. I also tried to plug it into the TV in the bedroom and it does the same thing.
I've had this happen to me on 2 separate ROKU Ultras (pre-2019 version). In both cases removing and/or replacing the microSD card fixed the problem. I know, makes no sense but that's what did it for me.
Roku has a thermal issue with its chip which cross-talks when it gets hot. This cross-talk pathway increases over time because of oxide degradation on the chip circuitry. Roku never addresses this because they are incapable of doing failure analysis. They instead are trying to sell a standoff thereby allowing air to flow on all sides. You can do just as well by allowing the Roku to hang in midair by the RJ45 plug.
I have the exact same issue with my Roku Express 4K+, when I got the unit beginning of September then it installed just fine and worked, I went out of town for two months and now the unit has stopped working. I have reset it, moved it off power and reconnected, changed the hdmi ports, the dancing Roku icon appears when I take the power on and off and on again and then no signal. I changed to this unit from my older Roku which was working just fine because Roku said the support for the older version was ending, I kind of feel cheated now.
I'd be happy to take a closer look to see how we can help get you up and running. A few questions here to better understand what you're experiencing:
How are you powering your Roku device?
Is the device plugged into the TV USB port or is it plugged into a wall outlet?
Have you already tried performing a factory reset on the device to see if you can get past the bouncing Roku logo screen?
As a last resort, if you are still experiencing an issue, we would recommend disconnecting your wireless network, then rebooting your Roku device to see if your Roku device is experiencing the same issue. Once the device is getting past the bouncing logo screen, try reconnecting your wireless network.
The device is powered using the power adapter that came with the unit, it is connected to a power strip and then connected to the TV by HDMI. I have tried factory reset button but still no luck, same behavior, the dancing ROKU logo appears and then nothing, no signal. Tried different ports as well.