installing linux mint in AHCI mode on alienware 14 (dualboot with win10)

I've had a dualboot with windows 10 and linux mint 17.2 for ages using grub as bootloader but decided to upgrade to a samsung 850 pro ssd.

Since samsung reccomends setting te sata mode to AHCI I did that and reïnstalled windows. it works perfectly with grub2 as bootloader.

Now I tried to install linux mint 17.3 and it wouldn't launch from disk / usb.
Grub launched, but as soon as I tried to launch linux mint 17.3 (in default or in safe mode) the screen would turn black, a fan spinned up, spinned down and nothing happened. that's it.
So I tried mint 17.2 (from usb and disk), same result.
Then I tried to boot in legacy mode, that worked!
But grub2 can't launch win10 in uefi mode when grub2 is launched in legacy mode :(.

I noticed that there is an ATA mode, RAID mode and a AHCI mode.
While I'm pretty sure I originally installed mint when the bios was on RAID mode, It won't launch now in RAID mode. (haven't tried ATA since not reccommended for my drive ad I'm pretty sure I've never used it.)

The ubuntu and linux mint forums say that this is probably a drive problem, where it would most likely be my graphics driver.
I don't think that's the case because I hear the fans spin upand don't hear disk activityafter I select a boot option and just go to black screen.
If it was a driver problem I should get an error message or hear the pc boot, but not be able to see the display afaik.

Any help is grately appreciated.