K-r not working!!

Hi I was In the middle of shooting a 70th birthday party tonight when my k-r decided to stop working, it doesn't always switch on and when it does it just clicks constantly. I cant see anything in the viewfinder when it does this. I changed batteries and memory card but it's still doing it. I had to leave the party with my tail between my legs, can anyone help.?

Try cleaning the contacts on the lens and the lens mount with isopropyl alcohol.

Regards
David

I'll get some tomorrow, thanks. I've just switched it on there and it's now showing a red thermometer, does this mean it's overheating? If so how long does it take to cool down again?