Since the original manual is fragmented, here are the verified specifications for the MIH61R MB 10097-1:
: The official OptiPlex 390 Owner's Manual covers hardware installation, component locations, and troubleshooting.
Since this is an OEM part, there isn't always a single "retail" manual. Instead, use these resources: Go to product viewer dialog for this item. ZEBRONICS H61-NVMe Micro-ATX Motherboard
The is a micro-ATX motherboard commonly found in Dell Optiplex systems (such as the 390 series) or used by OEMs like Foxconn. Because it is an OEM part, a standalone retail "manual" is rare; however, you can find the necessary setup details through OEM support archives or Dell’s Optiplex 390 documentation. Technical Specifications Chipset : Intel H61 Express. Socket : LGA 1155 (Socket H2).