I have a brand new Das Keyboard Model S Professional that I just picked up the other day. I have it connected via USB – while I would like to use PS/2 for full n-key rollover, the media keys (and sleep key) doesn't work over PS/2 so I've reluctantly fallen back to USB for them to work.
However, after resuming from sleep, the keyboard doesn't work. It doesn't appear to be receiving power, and it doesn't appear at all under the Device Manager. (The USB hub on the keyboard does appear, however.) If I restart the computer or unplug the keyboard and plug it back in, it works again until the next time the system resumes. If I resume the system through some other method that doesn't involve the keyboard (e.g. clicking the mouse or pushing the power button on the case) the keyboard does work fine. This only seems to occur if I push a button on the keyboard to resume. It will appear to get power briefly (the num lock, caps lock and scroll lock lights do flash briefly) as the system resumes but it stops working after that.
I tested on a different Windows 7 system (my laptop) and I cannot reproduce this at all on that system.
I've tried the following:
- Disabling USB selective suspend in the active power profile
- Disabling "allow the computer to turn off this device to save power" for the USB Root Hub device the keyboard is connected to
- Adding the registry DWORD value ForceHCResetOnResume for both the HID keyboard device and the USB Root Hub the keyboard is connected to
- Negotiation tactics which may or may not have included anger, threats of destruction and tears
The keyboard is connected directly to an ASUS P8P67 Deluxe motherboard (Intel P67 chipset). The BIOS and chipset drivers are both updated to their most recent versions.
Any suggestions?
Best Answer
I have the same problem on Linux (Ubuntu). In fact, it has nothing to do with your OS or hardware. It's N-KEY Rollover's fault. Using it over USB involves some dirty trickery, and not working after resume is part of that.
In other words, the fault is in the keyboard, and probably the only way to solve it, is to not use it over USB (but then other things won't work...).
Some info regarding this: http://www.overclock.net/t/491752/official-mechanical-keyboard-guide
EDIT:
I recently discovered a workaround to get the keyboard working after resume, without having to unplug and replug it in: it is sufficient to just plug anything into its USB hub, and the keyboard should start working. At least in Ubuntu it works, not sure about Windows.