I have a new Roku express. I have successfully installed a different Roku on a different TV. This Express install went fine until the device looked for updates on the initial install. Then it has been stuck on the logo screen for days. I have reset the device probably ten times. Changed batteries in the remote. Changed HDMI ports. Unplugged. Replugged. Reset the wifi modem. Nothing is helping. Still bouncing
Some people with this problem have reported success by using a wifi hot spot on their mobile phone as the internet connection. If/when it completes the update successfully then they could switch it back to using their home wifi network.
If you don't have a phone hot spot available you could take it to a friend or neighbor's and try using their wifi for the update.
Note: this has not been universally successful, but many people have reported it worked for them.
I have gotten the device to reboot twice. I moved the wifi extender into the room. There is plenty of service. The updates download. The counter gets to 100% but then the loading circle stops for about a minute. It says don't turn off the TV. The system will reboot automatically and then it just stays the bouncing logo for hours. I tried changing batteries in the remote to see if that could get me to a home page. Nothing.
I have yet to come across an actual fix for this that works across the board. It does seem like it occurs with the flashing of either the firmware or software during the update. It seems to be hit or miss with the Express models. Wish I could offer you better advice other than just returning it. Other than the Factory Reset (Holding/Pressing that little Reset button for 30 seconds+), that is the only way to restore to previous condition. It could simply be a defective device or a corrupted software update.
As you saw with your other Express setup, they should just be plug and play. Basically the standard troubleshooting is to make sure you are plugged into the wall, not the tv, to eliminate a power supply issue, and to Factory Reset the device with the extended holding of the reset button. (debateable whether this is necessary, but sure can't hurt anything.)
If you still wanted to troubleshoot, I guess you could Factory Reset again and try to see if you can get through Setup on that other TV where you have a working Express. Maybe the non-working Express is just having issues during setup with the particular TV at the moment. (it could be a display or resolution issue). If you can get through setup, then you can switch back to the desired TV after everything is working. Right now, you at least know the other Express had no problem during setup with that other tv. (a known good condition). If the non-working Express won't complete setup in a similar manner, then reasonable to conclude the device is defective.