I don't know why people keep using these old PCs that consume 70w+, buying a new board is going to save itself by the electricity cost if you're going to be turning it on 24/7.
My Rock64 consumes 1.5w, which is going to cost about 20c/month, which is almost nothing.
I have Pentium G4650 that consume about 13w, which will cost about $2/month.
A 70w PC will cost about $10/month. That's $120 a year. You can get a new PC for that cost.