What's wrong with my Worcester Bosch 24i Junior Combi Boiler?

Hi, I've come home today to find I have no heating/hot water and a boiler that I thought had a frozen condenser pipe (I've suffered from that before). Reset it and it tried to fire up but failed and locked out again. Took off the front panel to check the reservoir but it wasn't full. However, when I turned back to the boiler having put the panel on the floor I noted all lights had turned off and the boiler is now unresponsive to pushes on the power/reset buttons. I haven’t touched the power supply to the boiler but the cover was a bit of a job to get off and there was a bit of a jolt when it came loose. The only thing I get now is a slight "twitch" on the fan every other time I press the power button. On the other presses a slight "ding" sound can be heard. I've posted a video of it here.

The only other thing is that it has no pressure. I'll re-pressurise it tomorrow once I've borrowed an internal filling key from a friend (mine's missing!)