@uradmonitor I can eliminate the Settings screen as being a contributor to the issue I’ve been having with the SD card going offline; so that leaves:

• it connects to wireless (after not being connected)
• the screen is on (possible factor)

@Wouter – once I worked out that the GPS antenna cable was damaged and was able to work with/around that, my GPS reception went back to excellent. The trouble is that I don’t know how long it was damaged for but I’m assuming that most of my GPS issues can be attributed to it. Since I sticky-taped the antenna cover on after I fluked it into a working position (after the photo request), I’ve had little issue; I know that my workplace is a Faraday cage (metallic window tinting), just like planes are, but, aside from that, it’s been pretty solid. In the place where mine spends most of its time when I’m at home, it’s 4m from some French doors (upstairs, two-story townhouse, corrugated iron roof) and typically has 5-7 satellites.

I’m yet to try any of the antennas that I bought, partly due to the fact that it’s working and partly due to time.