the the 2 fault lights are on the comparator board.A comparator trip occurs when the error voltage exceeds 40 millivolts when the unit is running. it can be caused by many things including tripping a door lock in high speed, losing the safety circuit in high speed,and other internal problems in the op-amp,pulse firing, field firing,SCR's and many other things. you reset it by toggling the switch on the board, if it trips with out trying to run, you may have a problem in the Field 3ea,or op-amp 1ea-2ea boards. Or the Comparator itself could be out of adjustment. Connect a DC meter black lead to the common terminal and red to the trip point terminal. You should have 4 vdc. you can cheat it up a little if you are getting nuisance trips. then connect the red lead to common and black to trip terminal, you should have -4vdc. The op-amp, and 3ea boards are plug and play. If you have spares you might try those. The heat would have to be up over 105f or more to cause a trip, but I wouldn't rule it out.Good Luck.