The only thing left was either the tube going from the regulator to the solenoid block, or the regulator itself. To test the regulator, I unscrewed the propane tube from the solenoid block. I reset the regulator "one more time" just to eliminate that as a possibility. Then I attached the regulator to a full tank (OUTDOORS!!), and slowly opened the tank valve.
A steady soft hiss and a pungent odor would mean the reg is ok. But if you hear nothing, or it sounds like a tiny stuffed up nose, the reg is bad. Mine made no sound, it was totally plugged.
The Defender regulator is a Marshall Controls Model 150, which is used on many gas BBQs... Char Broil Replacement Hose and Regulator part # 83559 uses the exact same regulator as the Defender. Lowe's sells it for 20 bucks. The hose & fitting are different, so I attached the old hose to the new regulator with a small hose clamp. After putting everything back together, the unit fired right up and has been running ever since.
These regulators are intended for outdoor use but are supposed to used under a PROTECTIVE COVER. If you consider how many MM's are outside exposed to the elements, which is to say all of them, it's no surprise the regulators eventually fail.
Some other thoughts:
1) A MM Defender is a VERY SIMPLE device. As long as the controller board is working and the catalytic converter is sound, the device can be serviced with off the shelf parts.
2) There is no need to use CO2 to blow out the unit. There are no parts in the MM that could be harmed by using compressed air in place of CO2. (Think about it - the thing is full of air all the time anyway) Compressed air works just as well - which is to say, it works okay for certain problems. But if your MM is really dirty, crack it open and replace the nozzle for $5.00.
3) If you're about to take an aluminum bat to your MM (I was THIS CLOSE) please don't do it. There are only a few main parts that will go bad and by process of elimination you can fix it.
