Photo of mainboard needed urgently!
Board was inside "dead" Robox, being used as parts now, with extruder removed by another, un-powered, with no USB cable or power cable fitted, and so "in situ" measurements. Motherboard or logic board was intact though, so nothing unconnected as such. 🙂
Obviously there might be other components in parallel with these, as I haven't seen any schematics for the board anywhere, so take readings with "a pinch of salt", but I'm guessing 689 is probably 681Ω with tolerances, & the 600Ω might be 590 or 604Ω using SMD components.
PS I believe you might have a parcel on the way too, so you'll be able to measure those. 😉