Yamaha - 2.1-Channel Soundbar with Wireless Subwoofer and Alexa Built-in - Black

Not sure if this relates to your situation or not. I also have my soundbar connected via the HDMI ARC port and noticed sound stopped playing from TV sometimes, usually after asking Alexa to play music or playing music from my phone through a Bluetooth connection. In my case when this happens I can get sound back again by pushing the TV button at the top of the remote. I noticed that the white LED light on top of the soundbar was on NET and needed to be put back in “TV” input mode again.

Just the hdmi cable should work. Just be sure to hook up the cable to the "hdmi arc" input on the tv...if not, it won't work.

So long as your TV has an optical output you’ll be able to use the soundbar system by plugging it into the optical port on the TV with the included optical cable. HDMI (ARC) allows you to turn the unit and the TV on/off using only your TV remote. Without that connection you’ll need to turn the soundbar on/off using a separate remote that comes with the soundbar. BTW, the soundbar and included wireless subwoofer sound great in our master bedroom. We no longer have rear speakers as we used to but for a bedroom audio system and for the price, this is a nice system.

Correct: no internet cable (CAT-5 cable) comes with unit, although the unit DOES have an ethernet (CAT-5) jack. If your house is wired for ethernet and you want to connect to the WIRED ethernet, then you have to buy an appropriate length of CAT-5 cable, then use the new cable to attach the soundbar's ethernet jack to the nearest ethernet jack in your house (i.e. ethernet wall jack). If your house is NOT wired for ethernet (or if you prefer to connect wirelessly even if you house IS wired for ethernet), the soundbar is able to connect to a home wireless network. However you have to use the "sound bar controller app" in order to do so. The app is the only way you can do things like (a) select your wireless network to connect to, (b) enter the network security key/password... You cannot do that stuff via the (very basic) remote that comes with the unit. I'm not a big smart-phone guy, but I did download the Yamaha Sound Bar Controller App to connect the soundbar to my wireless home network. The download/install process on my Samsung phone was free and surprisingly easy. Once you get the app installed then you can do all the network-selection/enter-network-password stuff required to connect the soundbar to your wireless home network. So the bottom line is you have to install the Yamaha Sound Bar Controller App on either your smart phone or a tablet device in order to configure the soundbar to be able to connect to a wireless network.

works very well with my 900F