I wonder if the broken wires on the Adcom amp would have done anything odd to the 990's output? Seems like a less-than-likely scenario, but it would also be odd to see a right channel pre-amp output and a right channel amp input come up lame at the same time - and there does seem to be something amiss either at the 990's pre-amp output or in the speaker cable itself. Have you tried swapping the left and right pre-amp cables at the 990 to see if the problem shifts over to the left speaker (indicating that the right pre-amp output is up to something)? As for getting help from Outlaw, just give them a call and bring them up to speed. They'll work with you on it.