My Quest has had a dodgy antenna for some time now. Poor electrical contact inside. I have taken it apart, tried to re-solder the connection but it was still unreliable.
I tried an external antenna, which worked, but was a bit inconvenient.
Maybe it was time to buy a new Zumo ....
.... but then I spotted on Garmin's website that they do a fixed price repair or replace for just £65.
Sent my old Quest off on Monday, got a replacement unit on Friday.
It was pre-installed with 2009 Maps, and when I checked on-line my registration had been updated with the serial number of the replacement unit and a new unlock code for the software.
The replacement unit is guaranteed for 3 months, and the new maps would have cost £78 alone.
I call that a pretty good deal.