I should start, possibly, by saying I am no expert on offline SMPS, but am having a go.
I am getting no proper voltage out of the outputs. The transformer outputs are switching to negative voltages.
The image below shows:
Yellow (bottom trace): FET gate (Q1 pin 1) Green: CTL (U1 pin 7) Blue: Protect (U1 pin 6) Purple: Vcc
The be absolutely clear, the bottom trace is a train of 17 pulses. The gate pulses are less than 1us, in the region of 700ns, which strikes me as being way too short.
The optimer pin on U1 doesn't seem to move. Vin_sense is bang in its correct range, I have an output load, but I'm not by any means stretching the transformer.
I have also looked at Isense, and below is the same type of scope traces, but with top trace as Isense, not Vcc.
I've read and re-read datasheets and apps notes, and although I did find three things with the original schematic that I have fixed to reflect what's in the above schematics I can see nothing else obviously wrong.
FWIW I am currently supplying the input voltage from a bench PSU at 142V, not yet directly from mains.
Do the very narrow pulses seem wrong? Can anyone see anything I am doing wrong? If you want some more scope traces or info, please ask.
The data sheet can be found here.