The "control unit" (function, temp, timers, etc.) on my old stove is on the fritz. The manufacturer doesn't make them anymore. When you can find one they are very expensive.
A couple places do rebuilds on control units for appliances -- ranges, dishwashers, others. You send in your broken unit, they fully refurbish it and send it back. From their eBay reviews they stay very busy from retail consumers -- 100's per month on eBay alone. An interesting business and valuable service.
Interesting cycle from repairing your old appliances using manufacturer parts, to having to use aftermarket parts, to scrapping the whole appliance and buying a new one, back PAST replacing the part to having the individual component remanufactured.
This type of niche business made possible by the internet.
New control $429
Rebuild services: $140 - $290 with shipping
New Thermador range: $5,000
4 hours ago