All fixed. Cost more in postage than the parts required!
The source chain consists (after the mixer) of 2xERA3s 1xERA4, a small tranny and a big bolt down jobby, thankfully the latter 2 were fine and just the 2nd ERA3 and the ERA4 were Kaput. No idea why this'd happened. They were still taking reasonable current. Very easy debug and fix and put that down to the excellent build quality and construction. A joy to work on!
