Hi Robert_at_lane,
I had the same problem as you the last days and I also tried the different solutions posted here in the community I nearly gave up but today I tried it the last time on a different way and it seems like it is working now. Graphics card is still there and isn't switching off anymore even if I use programs which need a lot of performance, also waking up is working super fast again without any problem and the power button is working as well. (I guess there is some issue with the power management because when my power supply was plugged in the power button and the startup worked, unplugged I could press what I wanted, only the detach button was waking up the device and the Nvidia cards always disappeared after a short time except when I was using Rhino3D plugged in with best performance)
Maybe my solution helps you as well....
- Make sure that all windows updates are made and the latest firmware is installed, also the latest Nvidia driver (397.64)
- Put the power settings to best performance (plugged in and in battery mode)
- Open the device manager and keep it open
- Unplug your SB2
- Detach the tablet and wait for ~10-15sec until the system updated the connected devices (the device manager should flicker once or twice until it stops, maybe there is a sound as well)
- Reattach and wait until the Nvidia card pops up in the device manager
- Quickly make a normal shutdown as long as the card is still visible in the device manager
- When the device is off, do a hard reset by pressing the volume up button and the power button for at least 20 seconds (Press and hold the volume up button before pressing and holding the power button)
- The UEFI interface might appear, just exit and let the system restart.
These steps seemed to work in my case...I hope they help you as well...if there are any changes during the further use of my SB2 I will inform you.
Best regards.