This sounds like a main board failure, END light and Start light on, with all other lights off translate to error F12, the website here explains how this is calculated.
I would recommend getting an engineer out to strip it down, if you provide me your post code I can recommend someone in your area.
Looking on line at the spare parts, you can pick up a new PCB here for £150, which by the time you have paid labour costs its probably uneconomical to repair. The flip side is it may simply be a lose ribbon cable which needs reattached to the board.
I would suggest you use Spin Doctor, we have had alot of customers who have come back and given positive reviews for the work they perform. They charge about £40 to come out and quote for repair, and a further 40-50 to replace the part if you wish them to proceed. They should have availability early afternoon\now if your free, if not can fit you in Thursday, their number is(###) ###-####6948