I'm nowhere as good as @Jake, but I did find this thread on Reddit about something similar?
They mentioned reset, so maybe this isn't exactly what you wanted?
https://www.reddit.com/r/symbian/comments/n7o2su/nokia_9210_communicator_reset/
Quote
Hiya guys! I recently revived my 9210 communicator from 2001. The phone side of things work perfectly, I can make phone calls and battery holds.
But the communicator side is just flickering on and off on the nokia 9210 logo.
Found it, it's crtl+shift+f during boot.
Edited by torch 2023-08-31 5:32 AM