Samsung LE40M86 LCD TV changing channels by itself!

I purchased a Samsung LE40M88 LCD Tv over a year ago, after three months of having it, I got a problem. When i would switch it on it would flick through all the digital tv channels for about an hour and then settle on a channel, and I could then operate it as normal. There was nothing i could do to stop it. As it was under warranty I had an engineer come out and fix it, apparently he replaced the motherboard! It worked again ok for about 10 months and now recently it has started doing it again. Also, if we leave the tv on standby it sometimes switches itself on and then continues to flick through all the channels so we have to make sure that we turn it off by the plug. It is now out of warranty, I know that they replaced the motherboard before - do you think i could buy one and do it myself? Pleasssssssse does anyone have any suggestions on how to fix this problem? Thank you

Movies 24h | Dmart.vn