Issue started maybe a year or so back. Power level is randomly and frequently erratic at obviously higher level (100%?) than set when below 100%. This micro has a turndial rather than keypad to set time/level, and it seems to accept the power level setting (i.e., 30%, 50%, etc.). I've never noticed it cooking at a lower level than set, only higher. Sometimes overpower is immediate -- such as setting for 10% and have boiling food within 30 seconds -- and others it's completely unpredictable. For example, if time-cook that seems to be working properly based on food temp is interrupted, the restart of the remaining time may immediately overpower. Or, it may complete one or more uninterrupted time-cycles in a row correctly (OK for 2 mins/30% - stir, 2 mins/50% - stir) and then the next time-cycle immediately overpowers. It's getting to be a real pain since I have to constantly monitor all cooking all the time to avoid overheating. It's a 12 YO micro but other than this problem I really like it and don't want to replace if I don't have to. This seems to be kind of an uncommon problem, with all the searching I've done mostly resulting in the opposite issue of no heat/failed magnetron. And it isn't the entire micro mechanics overheating (no odor, buzzing, burn spots, etc.), only the power levels. Is it fixable or do I resign myself to buying new?