Hate to sound like Joe Obvious, but where did you get the 50V max from and
is that max for each input voltage or a potential across them?

The one thing that jumps out with the above is, +25 and -25 gives a
working
voltage of 50V, if you see what I mean.


Never thought of that. It actually specifies +/- 20V on the board itself,
however I was measuring this with the convergence board disconnected - not
sure what the actual voltage is while under load, and now I'd have to
replace the IC's again to find out.
Not sure if I want to gamble another $50 on this thing or not.