The eMMC versions have a modified motherboard, where the HDD connector (at least), is omitted (just as the HDD/SSD version won't have the eMMC):just because the one he has does not have one does not mean there is not space and ability to fit one.
Reference pictures:
Genuine Acer Spin SP111-31 mainboard w/ Intel Celeron N3350 32GB NB.GL211.005 5056521927116 | eBay
Model (Family) Acer Spin SP311-31. The part has been pulled from a working device and it is in a very good condition. This motherboard does boot into BIOS. MPN NB.GL211.005.
www.ebay.co.uk
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