Great, the Sky Plus or Sky Box that you bought on eBay arrives and you hastily plug it in. Disaster, it's dead, stuckin standby. When you press the on or Sky button nothing happens! If this has happened to you then read this before blasting the seller as a crook.

Sky Plus boxes are generally plugged in and left connected to the mains for months or even years during which time they remain at a fairly constant temperature. Agreed there can be power cuts but these seldom last more than a few hours at worst. The trouble is all electronic items are made down to a price these days and this is particularly true of most Sky Plus boxes which, to the average user, are much of a muchness, all the same under the skin.

To keep prices down the manufacturers use components which are just up to the job and no more, after all save 1p on a million units and you make £10,000 more profit at the end of the run! One of the least reliable components in a Sky box are the electrolytic capacitors which are used to smooth out spikes in the power supply to various parts of the box. Now this type of capacitor can really be compared to a short acting battery. You push a variable voltage in one end, the capacitors stores up the volts, and pushes out a smooth voltage at the other end.

Capacitors have a sort of paste inside them which over time dries out meaning that the capacitor can store less and less electricity. The paste dries out through tiny holes that appear in the capacitor film - this is just the same as kitchen foil that has salt on it. Try mixing some salt with some cooking oil and leave it on a piece of aluminium foil overnight if you want to see what we mean. Now as long as the capacitor stays connected to the mains there is no problem as it has a built in ability to reseal any leaks. But as soon as a worn out capacitor is powered down it begins to deteriorate quite rapidly and no power means no power to repair itself so after just a few days it can easily become quite useless and require replacement.

So a box that was working perfectly well as long as it was connected to the electricity supply can become faulty while it is in the post. This can and does happen. The seller upgrades to High Definition and quite innocently sells his old Sky Plus box on eBay as fully working. While in the post some of the capacitors dry out and when plugged in it dies (often giving the fault that it won't come out of standby).

The other problem is that Sky Plus boxes don't have just one capacitor in them, one popular moel has 22 that can go wrong! So just because your Sky+ box won't switch on does not mean that the seller is a rogue, this may just be the first time that the box has been without electricity for so long.

Check if your eBay seller offers a guarantee, if they do then pay a bit more for that auction, you may well end up saving money in the long run!