I've got a pair of wireless 360 controllers that tend to turn off every so often.
I haven't touched the 360 in months so when the kids started complaining the 360 started acting wonky, I was ready to smack them for leaving the controller on the couch for the dog. But I digress....
Swapped the batteries, "re-paired" them with the 360, cleaned the contacts, but nothing seems to be a fix. Googled around and the answers are just as flaky as the controllers. Bend the tab? Buy rechargeable batteries? Send them back to Microsoft under warranty? You need to be kidding

I fiddled around with the controller and found that if you strike the controller on the grip just so (at the heel, where the motors are located IIRC), it powers off, thus loosing the connection to the big box.
So my guess is either the battery pack is loose, maybe from flattened springs? Or maybe a bad solder joint? Hell of a coincidence that both controllers exhibit this problem.
So before I dig out the security screw and open this thing up has anyone encountered such a thing before?