[Buck Waller]

I am a new owner that had this same problem and fixed my transistor pack. I am in the electronics industry and found that with mine the transistor thermal grease behind the transistor was dried up so there was not good heat transfer from the power transistor to the heatsink. This caused the large power transistor to burn up. The original transistor used was a Toshiba part that is now obsolete so I used a 25 amp part that I use at my company. It cost me $1.50 to replace this part and put thermal grease under the transistor to avoid a repeat of the problem. I can give more details to anyone who is looking to fix the same problem.