Hi,
Those screen are very sensitive. Some more than others.
The screen going white because the screen receives corrupted data due to electrical noise. So that's totally random and not a preenfm3 firmware problem.
When it goes back it's becayse a firmware background process detects dthat it oes not respond correctly and reinitialize it.
When it stays white but the sound engine is still working, it's because the screen keeps on saying everything is OK.
But with most preenfm3 that never occures.
I don't have this problem on any on my 4 developments preenfm3. And i let them running the internal sequencer with lots of screen activity for hours.
... but I don't think it's related to screen updates on the preenfm3, because often the activity is for channels that are not configured for the preenfm3
That's interesting. The screen can go white with midi activity on channels that does not correspond to any midi of the 6 pfm3 instruments ? So it does not trigger any screen activity ?
Do you have the screen going black with midi activity on USB ?