Quote Originally Posted by insearchof View Post
If this is often questioned I'm sorry. Here's the problem with Garmin Nuvi 250W not going past "GARMIN" without anything else start up status and will not go into preboot mode even tried all the software including garmincure3 (updater error pops up when attempting to start updater and will not do anything else). The reset button does not help either.
Is there a way to get HWID (I can open the garmin up if know where to look or serial number decoded?) even cannot use G7ToWin utility due to failing to enter into preboot mode?
If you have a backup of the file system look at your GarminDevice.xml for this: "<PartNumber>006-Bxxxx-00</PartNumber>". "xxxx" is the HWID.

An otherwise healthy device which has been 'bricked' can still access preboot mode. Try this method: First make and load Cure3 fw into Updater.exe then select the radio button beside 'USB Device'. Ensure the nuvi is completely OFF, you may need to force it off by holding the power slide to the left for ~10 seconds. Connect using a 'known-good' miniUSB cable to a REAR port only of PC [not thru a hub]. Hold the top LH corner of the screen before connecting the miniUSB plug to the socket and keep holding it firmly. If the device details appear in the windpw next to 'USB Device' immediately hit enter on PC keyboard or 'OK' with mouse cursor on Updater's GUI. Keep holding the screen firmly until the flash successfully finishes or at least until 'Loader' or similar shows on the screen.

If it really cannot access preboot then there may be damage to the flash chip, but it's not a common problem so unlikely.

The official garmin express, win updater will not find the 250W either. Even tried garmin usb driver. Did not activate when connected.
You must have Garmin USB drivers installed on the PC to use preboot mode for flashing. GE doesn't detect your device in preboot, only in mass storage mode.

@hancock
If you can't see it listed under Garmin Devices in Device Manager when it's in preboot then it's not reliably connected to PC or Garmin USB drivers aren't loaded. Reload the usb drivers and try different miniUSB cables and use Rear PC ports only [no hubs].