Hello Steve
You wrote :
"? With (2) and (3) LTspice points me to a problem that doesn¡¯t exist and not to where the problem does exist. "
A/
You are wrong for case (2) [ mixed Qd44 and 2sc ]. There is
Error on line 1137 : .endl 2sc6144sg
B/
" It might well have been more obscure to identify had the 2SC6144SG sub circuit been one of many included via .inc statements. "
Definitively not :
If you create a file with the 2SC6144SG subcircuit ( say 2SC6144SG.sub ), even with the uncorrect command .endS , comment the subckt command lines inserted in the schematic and use
.inc 2SC6144SG.sub? ? ? ? ? ? ? ?? ( and that's the right way to work? )
there is no problem in ALL configuration.
Regards
PhB