My firestick won't work on my tv. It's a Vizio HDMI model #D40-41.

When you open a video in kodi there are sound settings by pressing the main button.. u can adjust volume levels

yes if the firestick is registered to you

Plug the fire TV stick into a HDMI port on the TV. Plug in power for firestick. Change the INPUT to that HDMI port Main firestick screen should appear after 10-20 seconds

1. Plug your Firestick into one of the HDMI ports on your TV. Plug the USB power cable into your Firestick and into the wall or a USB outlet on your TV (if there is one)
2. Turn on your TV and set the INPUT device to the correct HDMI port. There should be a splash screen or setup screen on your TV at that point.
3. Using your Firestick remote, navigate to network settings and scan for your WI-FI router, Then enter the Wi-Fi password for your router (the same one you use for your smart phone or laptop).

You should be able to fully use your Amazon Firestick, and if you have Amazon Prime, be able to access all prime and free offerings from Amazon.

This is ducking bullship! So my TV is locked into wide mode when using any HDMI connection meaning my PlayStation and firestick are always cut off. Makes navigating the menu nearly impossible and watching always with picture cut off. It is a pretty old VIZIO model though. Think it’s time to take it to the desert and plug some .44 mag rounds into it.

Yes you can continue to use your cable. Firestick is connected to the HDMI port. You must have your tv source on HDMI to configure Firestick. Lastly, you must have a good wireless internet signal to setup Firestick.

suspect the firestick may be getting weak signal from the router.

A model number would be helpful...
The Vizio website is very helpful and has user manual available.
VIZIO Product Support and Services VIZIO

Sounds like your using an old HDMI cable. You need to get on that can handle HDCP. Walmart has a few decent ones that cost around $14 for a 3' cable.

The factory menu won't help you diagnose anything. If you are having issues on both HDMI ports, definitely check the cable and that the output works on the DVD player, try this on another TV if possible. If all else fails, call Vizio @ 1-877-MYVIZIO and they will send one of us techs out to replace the main A/V board, that should resolve your problem.