Unless it's something trivial inside, you can plan on spending at least $200 for a repair. Makes more sense to replace IMHO and E. What is the quote at your local repair shop? 
Also, you cannot mix/match with these proprietary/all in one type systems.
we have had our samsung home cinema HT-TZ315 for about 6 years now but recently the sound started to cut out and now it has gone altogether, we can't get any sound through the tv or my games console but if we put the radio receiver on the speakers work? could anyone tell me what may be wrong? or how much it would cost to repair? but if it is not cost effective to repair would it be possible to get a new cd player receiver without having to get rid of the speakers? thanks
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic