I'm having trouble with a Majestic (model # MBU36) gas log fireplace and hoping someone here could offer some suggestions... First, with the knob in the Pilot position and depressed, I can get the pilot to come on, but as soon as I let go (even after holding it depressed for 30-60 seconds), the pilot turns off. Occasionally, the pilot will stay on, and I'm able to turn the knob to the ON position. The fireplace comes on for a few seconds, then goes out. I've cleaned the tip of the the pilot to remove any dust, etc. and also checked the positioning of the thermocouple and the pilot. All seems fine. Could it be that the thermocouple needs replaced? If so, is this relatively easy? I haven't yet seen any how-to's on this topic. Where could I get the thermocouple? Thanks.