I've never seen a bad transformer in a switchmode power supply, ever. I also find that usually when I start to suspect a hard to find/exotic/expensive component, the actual fault turns out to be something simple.
IIRC the IIe supplies are self-oscillating converters where a resistor provides bias to turn on the transistor, which is then turned back off by a pulse from a feedback winding. If the resistor is bad or out of spec, the transistor won't turn on and the thing won't start oscillating. If you have voltage on the bulk filter capacitors (large electrolytics on the input) look around for a resistor that has ~320V across it and test that out of circuit.
I think the LC PSU is a bit under spec for a IIe. It may work fine with an empty machine but stick a few cards in there and it'll really be straining. IIRC the original IIe supply is close to 70W and the LC supply is about half that.
IIRC the IIe supplies are self-oscillating converters where a resistor provides bias to turn on the transistor, which is then turned back off by a pulse from a feedback winding. If the resistor is bad or out of spec, the transistor won't turn on and the thing won't start oscillating. If you have voltage on the bulk filter capacitors (large electrolytics on the input) look around for a resistor that has ~320V across it and test that out of circuit.
I think the LC PSU is a bit under spec for a IIe. It may work fine with an empty machine but stick a few cards in there and it'll really be straining. IIRC the original IIe supply is close to 70W and the LC supply is about half that.