What do they mean, obsolete? I have a Power Gear 1994 model, and its electronic controller is fine. Nothing obsolete about the solid state devices in these devices (I'm an engineer). They can literally last for 100's of years.
I would question the tech's evaluation.
Here's an idea, let us know the symptoms of failure you are having and let us take a crack at diagnosis?
On Edit: Oh, wait, did the tech say the controller is bad, and he can't find a replacement? That's why he's calling it obsolete? OK, I get it now. Never mind.