my xbox 360 e is not displaying and no sound comes from it

Try these steps first:

Turn off your console.

Unplug all the audio and video cables (including headsets) from the back of your console.

Connect only the HDMI cable to the back of your console. Then, connect the HDMI cable into an input for your TV.

Make sure the sound is not muted and the volume is turned up on your TV.

Make sure the console audio settings are correct for your combination of TV and cables.

Update your console software.

When playing back DVD Video or videos from Xbox Video, the Xbox 360 wants to encrypt the picture and sound with HDCP. If it cannot properly detect that the display can handle HDCP, or if the display is an older model which does not support it, then the Xbox
360 will show this message. I'm surprised it doesn't happen with Netflix.

A possibility is that there is damage to the HDMI cable or connectors interrupting the Xbox 360 from communicating properly with the display, leaving them unable to share keys for HDCP encryption (this is done continuously while HDCP remains active).

Make sure that you turn on the display first and let it fully "wake up" before starting up the Xbox 360.

Also, if you're using the original yellow/red/white AV cable for sound rather than an audio dongle, check if leaving the AV cable unplugged and only having HDMI plugged in will resolve the issue. If it does, then you might want to route the sound out of
your display to the sound bar rather than directly from the Xbox 360.

What brand/model display is the Xbox 360 connected to? Also, has it worked before on that display?

Make sure the AV plug is fully inserted on the Xbox 360 E. A loose connection can cause only one channel to come through.

.

Also, are you using the AV cable that was included with the Xbox 360 E for sound, or a separately bought, audio only cable?

well I have my own thread on this but what you do for the E it seems is I can run optical digital out from my tv to optical in on my AV receiver. This is straight from the xbox support site. You have to play with the display discovery mode on the console.
From my online search, it can go xbox 360 E hdmi to tv then optical out from tv to optical in on avr

Hello Evan_532,

Thank you for posting on the Xbox forums. We need a little more information to ensure that we provide the correct solution. Are you using RCA cables or a HDMI cable for your console? Have you attempted to connect your console to a different television?
Have you attempted to plug your video cables in to a different port on your television? Did this issue start occurring after a system update? Be sure to let us know the results!