Garmin, the GPS device giant, has issued a mandatory update targeted at correcting a widespread updating bug that renders them either useless or entirely inoperable. The bug causes affected GPS units to attempt to update their firmware repeatedly, and then either to shut down or lose their GPS satellite signal. Affected devices include the nuvi 7x5 series, nuvi 800 series, nuvi 8x5 series, zumo 660, GPSMAP 620 and GPSMAP 640.
If you own a Garmin nuvi 7x5 series device that is no longer able to receive a GPS satellite signal, you may download the firmware update immediately via Garmin's WebUpdater. Owners of other affected Garmin devices will be able to access the update in the near future, also through the WebUpdater. Registered users will receive notification of the availability of these updates via email.
On the other hand, if your Garmin nuvi 7x5 series device is no longer able to power on, a return authorization is required so you can send the unit back to Garmin for repair under warranty. To request a return authorization, follow the steps listed on this page in Garmin's Knowledge Base.