You don't actually need the Acer manual. This board is based on a standard Intel H81 chipset. Here is everything you actually need, for free:
desktop series (such as the M2631G or X2631G). While Acer does not provide a standalone manual for the motherboard itself, you can find complete documentation by searching for the parent desktop model on the Acer Support Site using your SNID or serial number. Because this board was manufactured by ECS (EliteGroup)
If you need a specific diagram for the or USB 2.0 headers ,