My work computer (i7-7700, 64GB RAM) runs Linux Mint 19.1 and Windows 10 in dual boot. This used to work fine, it normally booted Mint unless I pressed F12 during startup and told it to boot windows.
A while ago, the internal graphic chip reached it's limits, so I received a "Sapphire GPRO 4200 4G GDDR5 PCI-E QUAD MINI DP" graphic card from our IT guy and installed it myself. Without needing to install any drivers, Linux booted properly and all three screens work.
The only problem: There is no more POST screen. All displays stay black until the linux mint bootscreen shows and boot is halfway done. Therefore, I don't get the opportunity to press F12 and boot into Windows anymore. Could anybody please point me in the right direction of how to solve this?
So far I tried:
trying two slightly different drivers (amdgpu-pro-18.20, two versions, one from sapphire, one directly from AMD). the install seems to work, however the Graphics card is called "Advanced Micro Devices, Inc. [AMD/ATI] Venus LE / Tropo PRO-L [Radeon HD 8830M / R7 M465X]" in the system info, not sure if this is right
I removed the graphics card and went back to using the normal graphics chip, this worked fine, I get my post screen back and can boot windows
Practicing when to press F12 and how to select windows using the graphic chip. I then tried the same with the card installed, didn't work, if I press F12, then down+enter like I normally would to select windows, it somehow aborts the boot process and I am stuck with a blank screen.