S9's are likely to be king of the hill for another while yet. If a fellow like yourself could find a way to bring some of those boards back to life I think you might just have a pretty decent client base.
Shouldn't be too hard. I know Antminer likes to chain their signal lines through the chips, either a source of chips or a single dead A9 should provide plenty of them and swapping those QFN type chips is no different from working on the TMS series power controller chips on the Titan boards.
That and power plugs are usually what blow these days. Plugs are fixable if you have the right tools. :-)
If you know someone who wants me to take a look point them to the thread. I'm going to be working on some S7's pretty soon, will see how those work out.
Thanks!
C