the docs for the MT7688 are pretty light for a MPU
I would suspect that Mediatek thinks of it not as an MPU, but an SoC designed to be a wifi router or a few related types of media boxes.
Crystals typically have two closely spaced but distinct resonances, and are intended and specified for use at one or the other in compatible type of circuit. The "Xin/Xout" style would likely be operating in a series resonance mode, while the one side grounded would be operating in parallel one. To get an accurate frequency you would need one cut for the resonance mode intended to be used.
If you are designing your own board at more than "see if I can" level you probably need to be in contact with Mediatek - not only for details, but to arrange a supply of chips. For an experiment, just transplant the crystal along with the chip.
@youlian-troyanov you're not missing anything. The confusion is in the specifics of my design. I using the Omega mini dock and powering the unit through it's mini USB port (5 vdc) eliminating a lot of custom wiring, cabling or converters :slight_smile:
I note that the picture of the physical switch actually shows a fifth solder connection - between 1 & 2 in your picture - and I observe that this is soldered on my Expansion Dock
I still don't understand just how this all works and how the switch is actually connected. @Lazar-Demin above says that the RESET_BTN is connected to ground when the button is NOT depressed. I still don't see how this works given the circuit diagram and your description of the button