Thread: Turn your Nuvi 510 into a Zumo 220

You've found preboot, but you didn't start flashing quickly enough so the nuvi has gone to the calibration screen.

This is the suggested way for your unit from [Only registered and activated users can see links. ], but i prefer not to use it if possible:

1. Turn off the navigator.

2. Click and hold the upper left corner of the screen.

3. Click and hold down the power button.

I don't have a 5xx to hand, but most nuvis can reach preboot even easier. This is what i always do initially when flashing fw and it works with most nuvis. Try this:

*Firstly, drag the rgn file onto updater.exe and have it visible on your desktop with the radio button selected next to 'USB Device:'. Position the mouse cursor over 'OK' ready to click.
*Plug a USB lead into a rear port of your PC, but not into the nuvi just yet.
*Hold the unit in your left hand, with your left thumb firmly pressing the uppermost part of the left hand corner of the screen and your fingers holding the unit from behind.
*Push the mini usb plug into the nuvi while watching updater.exe and as soon as you see the unit's details appear in the window adjacent to 'USB Device:' immediately press 'OK' button to start the flash. Maintain the pressure on the screen at least until you see 'Loader' appear and wait until it has finished successfully before unplugging the unit. It may reboot itself or you may have to turn it on.

Don't forget to do the NV backup and hard reset before and after the fw flash.

Also when do you turn the unit on?

ok, tried you method but I find that Updater never actually sees the Nuvi so I never get to press the OK button before if goes into calibration mode. I have the latest version of updater running on a Win 7 laptop. I've confirmed the USB ports work on the laptop and the Nuvi.

I have tried updater v2.8 and V2.7. Both are not able to see the Nuvi. Is there any chance that my Nuvi may have preboot mode disabled?