Thread: GarminCure3 tool - the new way to create cure firmwares for Garmin devices

I've come to the conclusion that, despite successfully pre-booting my nuvi multiple times prior to installing GarminCure3, some touchscreen or other unknown issue is preventing the device from pre-booting now and it is beyond fixing. I'm surprised I haven't worn a hole in the upper left corner of the screen by now. I've attempted multiple iterations of the power button, pushing other corners of the screen, pulling the USB cable in and out, you name, I've probably done it. I give up.

My situation is now like a scene from a war movie where the fatally wounded soldier tells his buddies to go on without him. Now I'll have to pull over and (DAMN!) ask for directions.

Originally Posted by steveor

Up until a week ago I didn't even know about pre-booting Garmins. What does it actually do to the device and how does the GarminCure3 aid in recovering a corrupted device?

GarminCure3 exploits the way fw_all.bin enters the mass storage mode. First, fw_all.bin boots almost completely, while loading maps and other files and writing the info about them to GarminDevice.xml (this info is used later by WebUpdater), and then it "reboots" itself with register R12=0xC. Second, after the reboot fw_all.bin enters the mass storage mode while not reading any files (though, it does read NV).

Sadly, if some files are corrupted (or even worse, the entire partition is not recognized), fw_all.bin crashes before "rebooting". And no mass storage mode is available.

GarminCure3 patches fw_all.bin and makes it think that it was called with R12=0xC. In this case fw_all.bin enters the mass storage immediately, while not reading any files.
But if NV is severely corrupted, it could still crash. There are other methods which could help in this case, but they also need pre-boot mode.

Letting the device sit with the battery disconnected did not resolve the problem. The nuvi just goes into mass storage mode instead of pre-boot no matter what I do. Oh, well.

Originally Posted by kunix

But if NV is severely corrupted, it could still crash. There are other methods which could help in this case, but they also need pre-boot mode.

What is NV?

Originally Posted by steveor

Letting the device sit with the battery disconnected did not resolve the problem. The nuvi just goes into mass storage mode instead of pre-boot no matter what I do.

Maybe it's because of some hardware problem?

Originally Posted by steveor

What is NV?

NV is a region in flash chip where firmware stores lots of info. Also while in factory it's programmed with your UnitID. Pre-boot mode issues are not related to NV. You can erase it completely and pre-boot would still work.

Originally Posted by Neil

You have this unit open? Disconnect the battery for some hours, then retry.

I'll give it a try.

The very first indication of a problem was when I turned on the device and it went into the white touchscreen calibration view. At first the device was unresponsive to attempts to calibrate it. After sitting a while it responded to calibration. But then device was caught up in a loop of loading the maps, rebooting, loading maps, etc.

By and by I did countless iterations of resetting, update attempts, screen recalibrations, etc. While attempting to force software updates in pre-boot the device never connected to the PC long enough to do that. When connecting in pre-boot mode the nuvi popped up in the System's Device Manager as a Garmin but then quickly popped out and the device went into the white calibration screen (I've read of others encountering this same issue but none were ever resolved).

Perhaps when loading GarminCure3, the device was in pre-boot just long enough to execute the program to turn it into a mass storage device. But now, because of a touch screen issue, I am no longer able to get into pre-boot to reload the original firmware. The device is too old to justify purchasing a replacement touchscreen to satisfy my curiosity though.