Fixing an Ergomotion adustable bed platform

So I've got an Ergomotion Series 100 that, years ago, began to fail in phases -- first, one of the massagers stopped vibrating, then another, and then finally the bed stopped changing positions. It wasn't batteries in the remotes, it didn't appear to be disconnected wires, and the remote code in the control box hadn't changed. Fortunately, it "died" in the flat position, and we've just left it there for a number of years.

Actually, to be clear, it's two twin size Ergomotions under a king mattress. Both of them eventually "died" in this manner.

But some time back I started looking to see if I could just get new controller boxes for these platforms. I recall having found them online somewhere, and they were pricey, so I didn't immediately jump on trying to buy them. This week I began this quest again, and I looked at the owner's manual, and of course I see that there's the controller box but there's also a head motor, a foot motor, a transformer, and the head & foot massagers themselves, on each platform.

So my question: Based on the phased failure of these platforms, is it likely that the problem is the controller box gradually losing communication with the other components, or is it likely that each of those components failed one by one? The difference, of course, is whether I try to obtain pricey controller boxes, or whether I need to buy all those individual components -- in which case, I'm really just going to need to get new platforms.