[SOLVED]A1466 - 820-3437 - Backlight works but only on low


I'm trying to find out if there is a problem with the actual backlight or the circuit.

I'm getting around 24v on PPHV_S0SW_LCDBKLT until the brightness is turned up, then it jumps all over.
I don't have another assembly for this model in stock to simply try another.

What do you recon the odds are that its the actual backlight in the screen thats the issue?