I bought a used Harmon XXV that is about 8 years old. I did a thorough cleaning and it started up right away. The only part that did not work is the igniter which I pulled out to replace at a later date. It stopped running after a few days with a complete electrical shutdown and I found that the fuse had blown on the circuit board. Upon replacement it started right up for a few hours then shut down again. When I went to check the fuse again I noticed two wires pinched on the wiring harness (The blue and yellow wires). As I tried to unplug the harness from the board to inspect the two wires shorted out and triggered my house circuit breaker. Needless to say the fuse was blown as well on the circuit board. I taped the wires, put in a new fuse, and reset my circuit breaker. Now I get nothing - no lights. Upon visual inspection of the circuit board, there does not seem to be any damage. What else can I check before buying a whole new circuit board?