C70 electric seat broken

[Squirtydog]

Please excuse the vagueness of the question but here goes. I am describing the issue as per the usual level of communication I get from my dad.

He has a 1999 C70. The driver's side electric seat no longer works. Apparently there is some lever / switch within the seat I think which he can reach in and press which allows the seat to work... Does this sound right?
He manages to to this fine but I was wondering if there is a permanent fix for this.
I think he has been told that it involves getting at the internals of the seat, hence is pricy.

My thought was to simply get a second hand seat.

Anyone have a clue what I'm talking about?

[foammanmark]

With my 850, I could hear the motor working but there was no movement. I followed this guide off youtube, and fixed it:-

[Squirtydog]

I think that this just does nothing at all. I think the 'switch' makes the proper switches work again.