What AC voltage do you measure at the two transformer taps of CR1721? One lead
of the voltmeter is at center tap, and two measurements to each side of the
secondary. No need to disconnect the bridge. Perhaps something is wrong with
the transformer given that you think all 4 diodes of CR1721 are good and caps
C1723 and C1722 give about right capacitance (their ESR could still be bad).
With the dimbulb tester disconnected...
On the primary AC side of CR1721, from the transformer centre point across the coils, one of the the readings measures 64 volts, whilst the other measures 130v
On the secondary (output) of CR1721, it measures 118v and 202 volts DC
But much more interestingly, and here is the face-palm moment... the +65v test point reads 110v, whilst the 140v test point reads 222.5 volts.
So the dimbulb tester was screwing up the voltages!!!
I must apologise for my lack of experience with these dimbulb contraptions
That leaves the question as to why R1726 smokes when connected the 127v mains supply?
The scope can't be left on the full mains for more than a minute...
James55