Hello heromanni. Welcome to the forum.
First - Disconnect the SSD, and any other connected hard drives, and try and get into the BIOS without it.
EDIT: If you can get into the BIOS, note your current settings, the perform a "Reset BIOS Defaults" (usually on the EXIT tab). then restart, enter BIOS again, and change the settings you need.
If that does not work then perform a Clear CMOS or CLRTC procedure:
- Shut down the computer > remove the power cord.
- Remove the 3v battery.
- Move the CLRTC jumper from pins 1-2 to 2-3.
- Touch a metal part of the case and Press and Hold the reset button for approx. 30 seconds to discharge all power from the board.
- Put the CLRTC jumper back on pins 1-2.
- Replace the 3v battery > replace the power cord > boot.
- Immediately go back into BIOS and reset all your preferred settings. If the CLRTC worked you will need to reset the date and time.
I would leave the SSD out while performing the CLRTC.