Problems with Sky plus box

[sanden]

Can anyone help me please. I am not really into technical stuff so need some advice.
I have a Sky plus box fitted about 2 or 3 years ago, and I did not take the Sky insurance. It is playing up now and I keep loosing sky channels and just get left with a plain blue screen. I have had to phone sky 3 times in the last week, which is quite an ordeal just getting through and going through the various stages. At one point a lady I spoke to told me to keep pressing the av button on my tv control - I then got cut off and nothing had happened. I phoned back and spoke to someone else and eventually got my sky channels back but when I started using sky I found I could not get tv guide or services. I phoned sky back and they said as I couldnt get services they could not help me. They said they could sent an engineer out for £65 minimum. I asked how much a new box would be and they said they dont sell them, but to try Comet etc. I have looked and they only seem to have a new starter pack which is no good to me.
Sooooo, any suggestions where I can buy a new sky plus box and get it fitted and set up, or any suggestions as to why my box keeps loosing its channels and leaves me only with tv channels. Could I have lost the services option when the lady on the phone had me pressing this that and the other on the tv remote?
I would appreciate any help - I dont really want to pay £65 for a sky engineer when my box may well be past its sell by date.

[AlBags]

Are you sure TV is staying on the Sky input? Using Scart lead and RGB?

Follow this through ..
and try a forced update to firmware.
Sounds to me like box no good/overheating.
Get one on ebay (low mileage) and when connected phone Sky to authorise it's serial.
Don't pay Sky for a quick sat installer issue. Find a local guy.

[sanden]

Albags, thanks for that. I will try someone local - but I have just changed the remote and for the time being everything is working, so will see how it goes. I am sure it wont lastfor long!! Thanks again.