Herman,
I should have asked, where are you located as this weill give us a better idea as to when to assist you
All desks with a serial number of BS11854 use the new motherboard, so I am guessing that with a serial number starting with "AW" would be before one starting with "BS' therefore I would think that it is the old motherboard.
Possibly the best way to check is to have a look at the Database and in particular the photos of the two motherboards (
https://www.sonido-7.com/d8b/maintenance.html#Post14 ).
Then have a physical look at the actual motherboard installed. As you will see in the photos, the new motherboard has the BIOS battery in the bottom RH corner whereas the old motherboartd has it in the middle of the board, just behind the exspansion slots.
That Dastabase page also has the BIOS settings for both boards --- just be sure to use the correct one.
If you don't know how to access the BIOS settings, on powering the desk, immediately hit and hold the delete key until the BIOS main page appears. If you are not sure how to move around the various setting, change the settings and save them, let us know and if not me then others will assist you. The first thing that you will need to do is to choose the option to check for the hard drive if you are operating the desk from the CF Card (forgotten exactly what it states in the list, but it is half way down the second column). It should super quickly flash that it is the CF card ---- just don't blink or you will miss it !!!!!
David