Rob:

You may want to try what Mark suggested, but if still intermittently fails to light up, look inside the front cover, you'll most likely see that one tiny metallic spot on the wire. This has been a problem for some of the older K80s, but not all. The repair is quite simple, or I could send you an upgrade kit and you can DYI. The upgrade kit is $90 plus shipping.

Good Luck,
Barry