Pop, bang, fizzle
I have working extruder and hot end and hot bed now, so ABS should work.
Sadly still not right. I did find one of the issues is that the hot bed was gently sliding about as I only stuck it down with velcro pads, and they become slippery at 115C! That explains some of the leaning TARDIS of pisa issue. But even with that fixed and things printing a lot better the X axis was "missing" still, and causing steps and problems. Annoying as this has all been fine for a long time with the PLA.
So replaced the X controller again, and this time, well, it caught fire. In fact three controllers in a row caught fire on various axis.
I think (hope) it is down to powering up in the wrong sequence, connecting the 24V supply with the controller active perhaps. If that is the case I can just be more careful and all will be well.
So plan is to get yet more controllers (they are like £8 each) and try being very very careful on power up... So a few more days to wait, sod it.