If you know that's a TL431 you have better eyeballs than I do. Or you have the same PSU in front of you, or a schematic (I could use one if it exists...).
I know it's marked IC330 or something, so it's not a transistor. I'm at work so I can't look at the board itself.
AFAIK, my remaining issues are in the inverter section, since with that disconnected I get a steady 12V that will power the monitor no problem (other than the backlights). Once I get my 2SC4672T100QCT-NDs from Digikey I can repair the faulty inverter.