appiah4 wrote:

Is there such an ATX to ATX adapter that just adds -5V? The only ones I know of are ATX to AT. The board I have is ATX but it requires -5V.

Yep, same seller on eBay that I linked above sells 3 different ATX no -5v to ATX with -5v adapters.

20-pin no -5v to 20-pin with -5v
https://www.ebay.com/itm/ANTRON-E20N-5VT20Y-5 … SA/262956124134

24-pin PSU no -5v to 20-pin with -5v
https://www.ebay.com/itm/E24N-5VT20Y-5V-EPS-A … SA/252903979500

24-pin PSU no -5v to 24-pin with -5v
https://www.ebay.com/itm/ANTRON-E24N-5VT24Y-5 … SA/262957463058