If you buy a new or second hand Sky+ box on eBay you will usually look at the signal strength and quality for both inputs (Sky+ boxes have two inputs while ordinary Sky boxes have just one input). To do this press 'Services' then 4 then 6. You may well see that the No.2 input shows as not working, DEAD! At the same time you will find that you can only view OR record one channel at a time, not both together which you should be able to do. If this happens to you DON'T PANIC (yet)!
The reason is often very simple - until you get Sky to turn on the recording part of Sky+ for you it is very common for the second input to appear dead. We aren't sure why this happens but it does and all you need to do is ring Sky and get the box transferred to your name and the recording switched on for you, then follow the instruction below to get both inputs working together.
Remember if you transfer your standard Sky card into a Sky+ receiver you will only be able to watch the non-premium channels that you subscribe to (such as Sky1, UK Gold, etc.) until you get your old card "married" to the new Sky+ box. So after ringing Sky you need to get the box to actually USE both inputs at the same time. The easiest way to do this is to set the box up to record two channels at the same time by pressing the R button on two seperate channels. Suddenly input No2 will come alive and will STAY alive even after you stop the recording!
Please note if it is input one that appears dead or both inputs were working and one suddenly stops then you have a real problem - now it's time to panic!
The cause COULD be as simple as a loose plug on the back of the Sky+ box or a problem with the double or quad LNB. Follow the Sky "connection check". It's a bit simplistic but does check these points for you. Try swapping the input 1 lead to input 2 and vice versa. If the fault carries accross with the swap then you can work out whether it's your Sky+ box or the LNB (or LNB lead) at fault.
If you have an early Amstrad make of Sky+ box then these have a known fault which can cause signals to first be unreliable and then drop out permanently (sometimes on one input but often on both inputs). The cause of this is component breakdown due to excess heat. If you are abroad let your Sky box breathe by NOT putting it in a sealed cabinet!