[majortom]

When you describe "humm" do you mean an audible humm coming from the speakers? Or a humm coming from some mechanical vibration of components, like humm from a transformer?

 

[majortom]

...the speaker is going off and on it will have some static then will go silent (no sound at all) then it comes back on and works a while and staticy again

For the audio cutting in & out problem, it would help to understand how your using the TV.
Are you using it along with an STB from cable or Sat provider via HDMI cable, or are you using it with an antenna for OTA reception (i.e. - no external boxes connected to it)? If using it with an STB from provider / via HDMI, can you connect it to an antenna, tune to a good channel and see if the audio problem goes away? eg. Temporarily eliminate any external boxes, HDMI from the equation if possible.
if the audio trouble turned out to be HDMI related, you might be able to use the Component Video connections, and analog audio inputs in addition to HDMI that ya could try and use as another test to further isolate.
We have a Samsung in the house also (LCD though), and I recall the audio never really worked right when using one of the HDMI inputs.
Don't recall which one. Wound up just using the Component video cables plus audio in, it's only in the kid's room.

 

[majortom]

Sounds like it may be ready for the repair shop.
Could be almost anything in the audio circuits, from bad solder joints on the main board, bad/leaky capacitor(s), or even an audio AMP IC getting ready to let go. Google around with your exact model / symptoms and see if there are others out there with the same issue. You may be surprised how common the same failures are with certain models/brands...

Long time ago, just for friends & what not, if there was a main board I couldn't fix myself, I used to send the main boards back to a depot service, they'd send you a repaired main board module and u'd have to align it to the Tube when ya installed it, etc. And they'd usually give ya like a $25-$50 core charge for the old one. Wasn't a bad deal at the time. Not sure what they do nowadays though...Bet there is still services like that someplace out there.