I checked the three caps, and C6415 is open. The other two read good
on my cap/ESR meter (about 400uF and ESR both < .5ohm). I'll definitely
replace the open one, and may do the other two as well.
Looking at the schematic, it looks as though I may be able to test the
board outside the TDR, with a couple of appropriate connections. This
would certainly make things easier.
- Mark N1VQW