@sledjunk
Well that's an inconvenient but not unexpected result. You're right about the log being incomplete but only insofar as it's simply reflecting the flash being interrupted. The commands to delete the gupdate.gcd file from .System folder and dump region41 (the nonvol memory) were completed however the 14_BUP.bin file is just full of empty FFs (indicating the region is empty, also not unexpected) however this is where the flash has failed as region14 is 16MiB in size and only ~10Mib has been dumped before it's fallen over. My best guess is that when it's hit the damaged part of the region is when it's failed. It may turn on eventually left connected to an external source but i doubt it. You could also open it and disconnect the battery for a while, that may clear any rubbish in volatile memory.

Unfortunately unless you can get it to power back on there is no chance for recovery however flash damage involving such a vital region is very hard to overcome anyway. There's likely no software fix available other than a very skilled programmer with intimate Garmin knowledge could conceivably remap the regions to exclude/ignore the damaged space, much like a few bad blocks can be isolated on a PC's hard drive or SSD. Otherwise only replacing the flash chip can restore it. That involves a lot of fiddly work as it's a BGA connection so the chip has to be carefully unsweated from the PCB and reballing is necessary when fitting the new one. Then it has to be reprogrammed. That's just not economically viable unfortunately anyway. [Only registered and activated users can see links. ]

Sorry i can't help further unless you can get it to power up, but from hereon it's probably all academic due to the fact that flash damage has made itself clear.

@Jonnay
You can get the GCD file direct from Garmin:
Code:
Please Login or Register to see the links
Use RGN_Tool ([Only registered and activated users can see links. ]) to make the RGN file and name it only 161301000400.rgn for safe flashing of either Cure3 or original firmware. You should try QuickCure3 first, it usually works ok and doesn't need the device's firmware at all. Still name it appropriately though. See here: [Only registered and activated users can see links. ] (Post #113).