Serial number location in maximus x hero

[JULIAN2057]

I have a Maximus X Hero motherboard. I threw the box some months ago and didn't write down the serial number. I looked into the motherboard and saw two number in 2 places under a barcode, however they didnt seem to work when I tried to update them in Asus product registration:

one is located above the dims slots and starts with 1854, the other is located in the atx power conector and starts with 1831. However, none of both works.

Could you tell me where I can find the SN? thanks.

[pndiode]

The serial number is on the back of the motherboard in the area around the CPU socket (white sticker/label with MB name and letters/numbers below bar code is the serial number).

The letters/numbers located on the sticker/label near or on the atx power connector is the MAC address for your motherboard.