Thread: Transform a Nuvi 37xx in a Nuvi 34xx for dummies

When you Geocaching you don't need all the time screen and you set to 10% and when you need to look where you ar, you set brightness to 50% and then again back to 10%

Nuvi 3790 only show custom POI but don't show food or other POI icon ( integrated in maps ).
You can convert 3490 --> 3790.

Originally Posted by popotnik

You can convert 3490 --> 3790.

Warning : from what I know cant convert a real 34xx to 37xx, Kunix told me he bricked one and cant restore it. Pm him before doing it .

Originally Posted by kunix

Looks like I've found why original 37xx bootloader doesn't work with 34xx firmware (Alviora, thanks for helping me with tests!).
I believe it's because 34xx firmware is too big, so the 37xx bootloader crashes while reading it. This also explains why some older 34xx firmware versions work fine with 37xx bootloader.
This issue could be fixed by compressing 34xx firmware and adding a special loader which would decompress it when executed. In a few weeks I will probably finish that piece of software and post here something for testing.

Thanks Kunix for making it clear

I have to add this too: From a practical user's point of view there is no good reason to convert a 34xx to 37xx, but there are in reverse. From a curiosity point of view it is interesting that original 34xx can convert to 37xx though.

One thing that has come out of all the results posted here particularly in [Only registered and activated users can see links. ] is that any earlier belief that 34xx and 34xx are uniformally identical hardware is unfounded. It does seem that they are reasonably compatible so far as fw cross-flashing is concerned but counter-intuitively and anecdotally in my personal experience it seems that the earlier 37xx have a GPS chip which handles the 34xx fw better than the chip in later production runs, although some 'unsatisfactory experiences' may perhaps simply be to do with software enhancement of accuracy not working. My personal theory is that the sw 'tricks' do not work. 'Hotfix' appears not to work properly in converts for initial 'lock on', so it's maybe reasonable to assume that other sw enhancements also don't work and therefore the cherished and constant fabled '3 m accuracy' reported by original 37xx is nothing but an illusion anyway.

It is easy and safe to flash back and forth with the 'Dummies' method though, and this thread was well named by Caty as as being for 'Dummies' because no real knowledge of fw is required.Anybody not sure of, or confused by, the unit's slow sat. lock on and/or reported accuracy in their 37>34 convert should read the thread linked above in particular the comparative test results described, and then replicate them the see the actual 'practical' accuracy of their convert using both this 'dummies' and kunix's alternate method from the other thread.

There is a topic that covers the subject of accuracy Nuvi 3790 converted into 3490
[Only registered and activated users can see links. ]

Note by MOD: Thanks for advice Is the same link of Neil in previous post:two is better than one