Ok,

I figured out what to do, decided to do one more round of experimenting, the FL5160 is very very sensitive to a stable/clean power source, so no idea how in the world their schematic concepts in the datasheet would work when trying to get a decent DC supply right from the AC mains, with very little filtering/smoothing.

I already have a DC Boost supply in this board for the LCD driver, which requires ~19VDC, generated from the 5V source, with the FAN5333B IC.  Just added a second setup of this boost circuit, providing a nice clean 12.5V or so source, plenty to keep the 5160 happy and avoid any brown out possibilities for under voltage.  (means a few more components on the board, but they are quite cheap, so not much added to the cost).

I really hated the requirement of having to mod the T962A oven itself changing out a transformer or whatever, as my approach all along for these designs is to truly be a 'drop-in' without having to mod the oven itself.  Of course in this case having an external 5" LCD does mean a little bit of a mod, but will be minimal.

Anyhow, I'm onto the main task now, LCD is fired up and powered on, looks good, seems to be booting up and no bad connections from what I can tell.. going to start testing some actual LCD sample code now from STMicro to see if it can actually talk to the micro correctly..

(I posted a photo so you can see my little debug/test setup)