Be careful using files of unknown origin. If you flash an incorrect ramloader (Boot.bin/Ldr.bin) you might kill it completely. The ramloader is flashed to rgn12, a virtual region, that in turn at the next startup will write internally to rgn5 (the bootloader) and rgn43 (the x-loader). The bootloader is like the BIOS/UEFI of a PC, if it's a completely incompatible one or it's missing the device won't start. Depending on the circumstances it might not be possible to correct that because in most Garmin devices rgn5 is protected from direct (external) flashing even if the device still turns on. However, if it's also not possible to re-write rgn12 either - because the device won't power on at all - it's finished. Garmin's boot method is quite similar to most ARM-equipped devices, but with a proprietary twist. If you want deeper understanding on that let me know, one of our guru members wrote a great explanation on it which i'll try to find.

RGN files have a safety feature if correctly named, the first 4 numerals are the HWID. In your US/EU fw 78 that's 1113. The last 3 are the software version without the decimal point, in our case it's 730. The filler 5 in between "01000" tells Updater.exe not to flash if on querying the device it receives a data packet identifying as it as having a different HWID. So, 111301000730.rgn is acceptable to flash only to a US/EU GPSMAP 62 or 78, but an RGN named anything else, even with just one digit missing in the middle, will be force-flashed to any device regardless of its HWID. Usually, we use OUT.rgn as naming for such a flash to make it obvious it's intentional.

Please post a link to the Indonesian RGN you tried, i'd like to examine it.

How did you go with the SD card method, did you attempt that yet?

As to the symptoms you're seeing, they're not indicative of any other hardware failure than a failing flash chip. It's possible to replace it, it's a BGA connection so not too hard for an experienced tech to source one and re-ball it. The problem is then reprogramming the new one, that takes special skills and particular equipment not easily found outside Garmin's factories. Garmin doesn't even do it themselves, they're a 'fabless' manufacturer like Apple and many others, so they send such devices if newish or still under warranty back to their appropriate contracted factory in Taiwan or China for refurbishment. They simply do 'like for like' exchanges rather than complicated repairs in local markets.

Agree, Australia is a beautiful country but indeed so is Canada. I've been there - you Canucks are just Aussies that talk funny i reckon ....