I just stumbled on this thread:
Unfortunately no resolution is given, but it occurs to me that if the guy’s oled screen only worked with a blade in, could it be that the oled wasn’t happy with a full 3.3 volt power supply, but fitting the blade served to somehow drop the voltage to the oled screen slightly, thus making the oled work?
As mentioned I’m exploring all avenues. In my case I’ve checked the 3.3 volt pad which is all correct, and I unpicked all four oled wires from the Proffie and connected them to my known oled test rig (thus bypassing this entire install and effectively connecting the screen to another build) but no change. Which suggests it is indeed the screen that’s faulty.
But maybe simply adding a resistor to the VCC wire to drop the voltage to, say, 2.8 volts might help? Unfortunately I can’t find any power specs for these screens, so I don’t know what their preferred voltage is. But at this stage it’s worth a shot. Will report back.