Ever since I've owned my Surface Pro 3 it's had the common problem that if I put it in sleep mode and pop it into my briefcase, then when I open it up a few hours later it's red hot and the battery's flat. Normally I work around this by making sure that it's fully turned off rather than just sleeping, but I'd still really like to fix the problem. So far, I've done all the obvious things: I've gone through all my devices listed in Device Manager and ensured that any device which has the option "Allow this device to wake the computer" has that option unticked. I've opened up a cmd window as an administrator, typed "powercfg -devicequery wake_armed" and verified that the response is "NONE". I've typed "powercfg -waketimers" and been reassured "There are no active wake timers in the system." I've verified that my Windows 10 installation and firmware are fully up-to-date. Nevertheless, if I put it into in sleep mode and I press a key on the type cover's keyboard, or even give the type cover a tight squeeze while it is closed, the computer wakes straight from sleep immediately. If I then open my cmd window as an administrator and type "powercfg -lastwake" it tells me "Wake History Count - 0". Clearly, the keyboard type cover is guilty of waking the computer up, even though it's configured not to do so and even though the computer denies that this is happening. Is there any way of fixing this that I haven't already tried?