This is an old thread but for anyone who comes across it I just wanted to throw in this thought because I would bet a nickel it may be a solution. CHECK THE PLUG! If it is not a resistor plug, find a resistor plug and change it. The is a classic sign. Resistor plugs will have an "R" somewhere in the part number. It's a simple 2 minute $4.00 thing to check. Good Luck, Tom