Most TVs will display a blue screen when there is no signal (via the aerial). Does the screen go blue during any programmes, and is it confined to some or all channels?
The old co-axial aerial connectors (called belling-lee, or UHF aerial plugs) are very prone to failure where the cable comes out at their rear, there is a claw which clasps on to the outer braided copper and inside there is a nylon insulator with a central pin. If the cable has been pulled at some point, it is possible for the braided part to come in to contact with the inner core, and the minute signal will be shorted out. The screen will go blue in this situation.
So, check whether any or only some channels are affected. Check the aerial plug. Check that the SCART connectors (big square connector with 20 flat pins in two rows within a metal rectangle that looks dented at one end) haven't become slightly pulled out of their sockets as they are prone to this if they don't have the full 20 pins.
If you view via a digibox, then is it satellite, cable or via the roof aerial (Freeview)? Let me know more info please.
Pete, August 2009
