I would :
1. Type in the manufacturers name into Google
2. Go to their site and type in the name of the motherboard into the search.
3. Blimey, lookee there, a place to download the manual! ;)
Galaxy Note 8 vs iPhone X
Graphic tees: 14 best websites to find your next T-shirt
How to update iOS on iPhone or iPad
Les meilleures applications pour enfants 2017