Potterton control panel not working?

A trip switch kept tripping the sockets and finally I discovered the screen on the Potterton control panel EP2002 was completely blank and the lights at the end of the sliders for the Hot Water and Central Heating were off. (I know nothing about such things - but the control panel looks dead.) The trip switch that had kept tripping is labeled 'RCD Switch' on my Temby switch box. Can anyone please advise me about what I should do? I couldn't fix it myself but I just want to make sure that no one tries to persuade me to get a new boiler or something when I try to get someone to fix it, so at least I can seem to know something when they quote me. (Incidentally, some years ago the Potterton engineers looked at it on several occasions as it wouldn't heat the water - the house had recently been built so Barratts asked them to fix it. One engineer ended up changing the panel but in the end the hot water never worked from that boiler in the kitchen so I've since only got hot water by putting on the emersion heater in the bedroom. So I only use the boiler in the kitchen for central heating.) I really hope someone can give me some good advice as I don't have much money and I'm dreading calling someone (what type of tradesman would I call anyway?) Thank you very much. Elle