Not a huge update, but a meaningful one: I spent some time tracing out the pinout for the headphone jack and power button FPC (the small sub-board that originally plugged into the N97's main PCB).

Since this is a cyberdeck from 2009, it obviously needs a headphone jack. 😎
Plus, having a physical power button is going to make the build feel a lot more finished and usable.

Using continuity testing and a bit of guesswork from the schematics, I’ve mapped:

• The 3.5mm jack left/right/ground

• The momentary switch used for power (which I'll use as a shutdown or wake GPIO trigger)

I'll connect this sub-board directly to the Pi’s GPIO header and 3.3 V audio out, or possibly route through a small amp if needed. The button will go to a GPIO with a pull-up + debounce.