Hi Bill
Thanks for the quick reply! Indeed I am using a 74HC595 in 'non-latching' mode. Thanks for that FPS sketch, it's really neat. I didn't know you could use if and elif statements for defined objects like that, super cool.
Anyhoo, I made a harness at work that has a 2x16 connector on one end for the LCD and the SR and everything else soldering in the middle, so I'd just have 4 wires going to the controller on the other end. I used the backlight anti-flicker with the series diodes and transistor but it doesn't seem to be working. Too bad I heat shrunk it all up before testing...d'oh! I can just snip off the LCD part though and try out your FET version.
You mention using a 1n4148, but I don't see it in your ASCII diagram:
// (LCD BL anode)---[ resistor ]---(vcc)
//
// (LCD BL cathode)-------------------------------+
// |
// D
// |
// (BL input)----[ 4.7k Resistor ]----+-------G-|-< (2N7000 FET)
// | |
// (0.1uf) = S
// | |
// (gnd) (gnd)
Would it go between the 4.7k/0.1uF and the gate of the FET (cathode towards the FET)?