[DEFECTIVE] colored rectangles at startup and no keyboard support (LP Alpha) - RMA Request

Hello, I have changed the Sata interface in Bios from Default to Gen3 and activated Legacy Support.

Since then, the internal HDMI port does not work anymore and shows the following on startup. IMG_20200125_082839.jpg (2.76 MiB) Viewed 4289 times Now I have connected a graphics card to the m.2 x4 connector and used the HDMI port there. Now the LPA boots into the UEFI shell, but accepts any keyboard input here, even before in the bios. IMG_20200125_100232.jpg (2.65 MiB) Viewed 4289 times IMG_20200125_100204.jpg (2.63 MiB) Viewed 4289 times I have already tried the following:
- 3 different keyboards (with and without cable)
- USB-C HUB
- USB from GPIO pinout (also here with the 3 different keyboards)
- Separate power supply to GPU and LPA
- Battery removed
- Hard Reset Trick
- Blind Bios Reset (F3 - Enter - F4 - Enter)

now I can think of absolutely no solution to reset the bios again...

hopefully someone here can help me.

With kind regards from Austria
Christian