I've had to replace the handset (mic and speaker) and the LEDs in the sign a few times since 2013, but I've mostly left the hardware alone otherwise except switching to Starlink in 2022.

Until then, it got Internet via Burning Man itself through what they call the "participant network", which they still provide: https://internet.burningman.org/

This consisted of setting up a Ubiquiti NanoBridge (then later NanoBeam) with their supplied config on top of a 20 foot tower aimed at the 60 foot radio tower near Center Camp. Sometimes they wouldn't provide the config or get the participant network running until like Tuesday or Wednesday of event week, it might at best provide 400kbit/sec total or have permanent 50% packet loss, or just be down for days at a time. It wasn't great.

I hear it has drastically improved in recent years, but I haven't tried using it.