Quote Originally Posted by Neil View Post
Unfortunately the TH JCV's are encrypted and 'locked' to their specific firmwares, as are all SEA jcv files. Even using a related SEA fw will not show them (eg SG/MA jcv's won't show on a TH fw model). Attempting to display them on a US/EU firmware Garmin unit will often cause a crash/reboot error, eg 1xxx units will crash. I haven't checked, but maybe your US Nuvi 3790 could be cross flashed with an appropiate local fw to read them, but such flashing is never without some risk, greater or lesser depending on the Garmin model. Search the forum if you want to try on your 3790.

To the best of my knowledge no modification of the Garmin iphone us/eu has been attempted to overcome this. It would require a lot of knowledge and work, but maybe the TN fw would be more adaptable?
No unfortunately last year I couldn't get it to flash to any firmware that would allow the 3790US to use Thai JV. Right now I am on SG 2.30, as it seemed to be the most stable. I haven't tried since Aug 2011 to flash to any other firmware to test it out. As for the iPhone, I haven't tested if JV works yet, but will do so tomorrow, but I am not optimistic.

As another note, I am in Bangkok, and the time is correctly set to local time on my iPhone, but the Garmin system believes the time is UTC -6, so Central/Mountain time in the US. I can't find a setting anywhere to change the time that Garmin believes it is. I have gone through all settings several times. So when I set a destination, it lists my time of arrival as 13 hours behind. For example, currently it is 4:00PM 15 May here, and a destination 5 minutes away would list an arrival time of 3:05AM, and since we are ahead in Thailand, that means it is calculating arrival at 3:05AM 15 May. Does anyone know how to correct this?

Thanks
John