JimboZA:
But I'm curious as to why they bother with the control electronics- buried inside a laptop where it won't get fiddled with under normal circumstances, and with a plug that prevents reverse polarity in the first place, it seems a lot of trouble or expense to go to.
Answer to both questions comes back to the folks doing the assembly. They are poorly paid labor in some place like China, or worse, who are given minimal training and have to assemble as many of these as possible in as short a time as possible. It is cheaper to make sure the unskilled labor can do it right the first time so someone else doesn't have to rework it. And there are less customers complaining about the fan not working.