Hooked up hd cable to ps3 and tv, now have no sound

Be sure to check the cables. You may need to replace them.

Try the cables with another component, if possible.

Also, try using AV cables to verify that it is not the TV and to simply troubleshoot:

To get back to default AV settings:

Press and hold the power button until the systems shuts off. (wait 2 seconds)

Press and hold the power button again until it shuts off again.

Once you have verified that AV is working, turn off console, take out AV cables.

Plug in HDMI cable and turn system back on. Switch TV input to HDMI and it will ask you if you would like to use the HDMI cables, select yes again and verify.

If you cannot get sound, again, check the cables..

If new cables do not work, then your HDMI output is going bad, not from use rather normal wear and tear of the motherboard.

To get the best non HD picture, you will need to get some 'component' cables, rather than the standard AV (red, white, yellow).

Good luck