Nobody really "fixes" motherboards. The cost would be prohibitive and requires extremely specialized equipment. Even motherboard manufacturers don't both with "fixing" motherboards that are sent to them. It costs them less money to simply replace the board with another one and throw it in the trash bin to be recycled. Just buy a new one if there is a problem, and in fact, I have to say, given the age of any board you are likely to find if you can't get it for extremely cheap it's probably money that would be better spent being saved to go towards a newer system that would likely give you about two to three times the performance for not that much more than what you might be able to find a suitable new old stock board for.
Unfortunately, right at the moment those Alder lake i3's with four cores and 8 threads are out of stock but should be back in stock before too long. You can get an 8 thread i3 that will easily give you miles better performance than that i7-4770, plus a motherboard with M.2 drive support and 16GB of RAM for around 300 bucks when they are in stock. It's a better option, but it also might be considerably more expensive if you can find a good condition board for cheap. Problem is, most used boards are going to have already lived most of their useful life so it's almost like throwing good money after bad.