Etrex Vista Hcx: GPS is OFF, stuck on Acquiring Satellites

I am posting this as a follow on from the thread: "Etrex Vista Hcx rollover problem" since that title does not describe the problem I had, or the exact solution (but almost does).

I put the trusty Hcx away fully working about two months ago. Fired it up three days ago for a camping trip, but it was stuck on "Acquiring Satellites", with no sign of any satellite reception (zero bars, nothing on the satellites display). This seemed very unlikely, as the device had not been knocked, dropped, since working normally. It was also displaying the wrong date and time, which it had never done before.

I found the diagnostic screen (youtube), and eventually did a full reset (Page up, enter, power on -- from youtube). All that happened after the reset was just before getting stuck at 'Acquiring Satellites' it flashed up 'GPS is OFF' -- which it wasn't.

This did seem like a firmware corruption issue, so I tried to update with 'Garmin Express' which doesn't recognize my Hcx, although does work fine with my Forerunner 220. Next tried webupdater. This seemed to show I had the latest firmware (3.20)

Seeing the thread on here ('Etrex Vista Hcx rollover problem') about the new 'Chipset M2 region file' fixing dates I tried to load this unsuccessfully.

Finally, using web updater I,

1: Reinstalled the latest firmware giving software version 3.20,
2: installed Chipset M2 region file' giving GPS SW Version 3.00 (this might have 0)
3: Reset again, and it started receiving satellites. After after about 10 mins it had a a lock, but the wrong time zone, So,
4: Set time zone, and all other preferences

Hope this helps anyone else with a similar problem with this very handy device.

jeremy