Mary, I had one similar to you. I was in the Manchester LLR heading back to Barton when the intercom stopped working. I realised I had lost comms and decided a fuse must have blown. I kept a good lookout and started to squawk 7600. After a minute or two or messing with various knobs and switches I decided to check the connections on my headset...it had come loose. Back to 7366 and normal ops. Check the simple things first and don't convince yourself that the cause of the problem is definite!