My setup: Toshiba R835-P56X laptop -> Amazon Basics USB 3 powered hub -> UGA-4KHDMI running 7.9 Beta 2 -> Changhong UD42YC5500UA TV. The TV is the only monitor (laptop lid is closed; VGA and HDMI jacks are both empty). This configuration worked fine under Win 8.1, except for one minor hassle. The TV turns off after a few minutes of no HDMI signal, so you’d have to press its power button when bringing the PC out of monitor-off or sleep.
With Win 10, if the OS ever ‘sees’ the TV off or still powering up (which takes ~10 seconds), all windows get resized to fit in 1366X768 (laptop’s panel resolution). Then, when the TV comes ready, one window randomly gets resized to 3840X2160 and displayed on top. You must manually shrink it as desired, then reset all the other windows, which have been shrunk and piled on top of each other in the upper left-hand corner of the screen.
Also, when the TV is seen coming back on, the default sound playback device is switched to the TV’s crappy speakers, instead of the good amp and speakers connected to the laptop’s audio out jack. I could connect the amp to the TV’s audio out instead, but then there is no sound if the TV turns off (e.g. if I’m just listening to Pandora, or if a Skype call comes in when the computer is not being used).
If I carefully turn on the TV and wait for it to become ready before touching keyboard or mouse, all is well. But, the least mouse movement (door slam, desk jostled, etc.) and the windows and sound get messed up.
Any fix or workaround would be gratefully appreciated.