Last throw of the dice this suggestion I`m afraid
If there is an option in the BIOS to restore the motherboards default settings please select it, save the settings, confirm that you accept the changes and exit, test the card slot, if no joy restart the notebook and test again.
If there is no option to restore the factory default settings in the BIOS then it can only be done by removing the MBs CMOS battery, this involves removing the keyboard to gain access to the battery so you may consider that it is not worth doing.