Apple Wired Keyboard intermittently disconnects

I hope this is the right place for this, keyboard isn't in the category title but it wasn't in any of the peripherals category.

I use the Apple standard wired keyboard with my iMac (27-inch, Late 2012, 10.10.3). On occasion after a short sleep period, the keyboard will disconnect from my iMac. It acts like the cord is severed. The caps light key won't even light up. I can change ports, use a powered hub, restart my computer, reset my SMC all that shiz and nothing will fix it. Sometimes after a wait of 10 minutes or so it will come back on by itself. If that doesn't work I have found that what always works and is a lot faster it to plug the non functioning keyboard into literally any other computer in the building, it immediately powers up and then I can switch it back for another 2-3 weeks of normal use...

What makes this all a little weirder is while the event is taking place I can use any one of half a dozen keyboards (3 of them being the same model as the problem one) with the iMac without any issue, even using the same USB port as the problematic one. And I've already swapped it out several times. So to be clear. No matter how many times I replace the keyboard, it will eventually stop working, but only with that computer, before being connected to another machine.

Can someone explain this? It seems to have started come up with Yosemite. I am running a clean install since I tried a "dirty" install and it rendered my system profile untruly useless requiring a very painstaking, manual restore of files and applications.