First off, thank you Steve for the help.
Sorry for the late reply - pregnant wife & housework takes priority over tinkering!
The PS is supplying 12.46V to the RAMPS.
With 12V off, there is no V difference between any of the stepper pins (Checking only E0 and X for convenience)
With 12V recently plugged in, there is an initial ~.45V between E0 1B and 2B. This decays over ~10s to 0.
Does this indicate bad POLOLUs?
There is no mechanical response with m119.
The dialog response from m119: (multiple lines of the same response statement, e.g. "missing line detected", removed for expediency)
14:38:40.620 : Printer reset detected - initalizing
14:38:40.682 : start
14:38:40.836 : 000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.0000ok
14:38:40.836 : Warning: Missed line detected - correcting buffer usage.
14:38:40.867 : FIRMWARE_NAME:Repetierttps://github.com/repetier/Repetier-Firmware/ PROTOCOL_VERSION:1YPE:Mendel EXTRUDER_COUNT:1 REPEd filament:0.00m Printing time:0 days 0 hours 0 min
14:38:40.882 : X:0.00 Y:0.00 Z:0.00 E:0.00
14:38:49.950 : ait
14:38:51.035 : t
14:38:59.136 : 0
14:39:02.152 : Warning: Missed line detected - correcting buffer usage.
14:39:11.359 : 24
14:39:14.445 : /0 @:0
14:39:17.546 : Warning: Missed line detected - correcting buffer usage.
14:39:28.784 : t
14:39:29.800 : 0
14:39:32.819 : Warning: Seems like we missed a ok, got a wait - continue sending.
14:39:48.208 : Warning: Missed line detected - correcting buffer usage.
14:40:12.766 : 44
14:40:15.737 : Warning: Missed line detected - correcting buffer usage..
14:40:34.044 : Serial com error

ystem.IO.Ports.SerialErrorReceivedEventArgs
14:40:58.043 : No start signal detected - forcing start
14:41:11.066 : Serial com error

ystem.IO.Ports.SerialErrorReceivedEventArgs
14:41:13.514 : No start signal detected - forcing start
14:41:34.269 : it
14:41:35.338 : :0
14:41:51.040 : Serial com error

ystem.IO.Ports.SerialErrorReceivedEventArgs
Thanks again,
Another Steve