Television and Home Theater

I have a problem with my television.  The picture randomly goes out.  It sounds like the cable has gone out when the screen goes black.  No picture or sound.  However I can still see the power light on the TV and hear that the TV is on in the back.  Does this mean the picture tube is going bad and time to replace it?  None of the other tv's in the house have the same problem so I don't think it's the cable. 

Anyone help or comments from ones that have had similar problems w/this tv would be greatly appreciated.

Yes, I have a Zenith TV that I use as a monitor for my comp, It is a 2004 model, as of late when I unplug the monitor it will not come back on for a period of time, after which it comes on and is fine. this has happened to me several times. The othe night Iunpluged it on accident and now it seems that is is not going to come back on any time soon. Do yu guys no pf anything I should try to get it to work before I take it to a tech..?

my tv: sony kdf55wf655 purchased 05/04/05

the problem: can no longer get local hdtv from off the air antenna(did b4!)

what i've tried ( summarized): connected outdoor,roof mounted antenna directly to uhf >scanned for digital channels>none detected ( analog comes in great) for example get channel 26 perfect but 26.1 'no signal'. come from same broadcast antenna.*sigh*

tried tuning directly ie; punching 26.1 in via the remote > NO SIGNAL