Thread: Convert 3790/3760/3750 to 3490

Originally Posted by aekhong

Do you mean we all can restore model number back easily after ergn,41 ?
Which way will you advice ?
How about Unit ID after ergn,41 ?
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I never deleted rgn 41 after flashed (for many times) with other firmware., just did clear NV by menu.

After ergn,41 UnitID will remain the same. But if you lose model number, you will not be able restore it back. At least it's not easy.

Originally Posted by voyager56

After ergn,41 UnitID will remain the same. But if you lose model number, you will not be able restore it back. At least it's not easy.

I agree. (At least for you and me ., to restore model number is pain.)
I will lost many features if 3750/3760/3790 --> 37xx.
To lost Unit ID is not my big problem.

Originally Posted by aekhong

I agree. (At least for you and me ., to restore model number is pain.)
I will lost many features if 3750/3760/3790 --> 37xx.
To lost Unit ID is not my big problem.

From my experience model number 34xx didn't mean less functionality. I think functionality is the same as for 3490.
I had an issue with lost Bluetooth, but now it's solved.

Originally Posted by Alexander2010

After installing unoriginal firmware good way to clear NV is
ergn,41
But you lose your model number (not big problem)
And NEVER erase regions 05 and 43 - it kill your device.

if erase then write before reboot will kill?
I tried to overwrite without erase before but it didn't do the job.

Originally Posted by bpb

I tried to overwrite without erase before but it didn't do the job.

Check syntax.
From Kanopus post on another thread:

Originally Posted by Kanopus

..... run rrgn,140,1:/dump140.bin, edit dump and run xrgn,140,1:/dump140.bin

No suggestion there of any need to erase ANYTHING before writing. If it didn't update you may have file path/name syntax error?

And current firmware 2.60 have too many small errors on non CN maps.

rrgn,41,1:/41_backup.bin
or
rrgn,41,0:/41_backup.bin

@voyager56
Interpreting syntax as:
rrgn, (command to 'read' region)
41, (region location number to be read)
1:/ (sdcard root directory)
or
0:/ (device storage root directory)
41_backup.bin (file name given to dumped data)

After installing unoriginal firmware good way to clear NV is
ergn,41
But you lose your model number (not big problem).....

@Alexander2010
I followed tutorial advice about accessing NVM menu to clear NVM. No ill effect on model number, so IF achieving same outcome it would seem to be safer method?

Leads to question: Is it possible to recover original (or change) model number by rewriting original rgn 41?

And NEVER erase regions 05 and 43 - it kill your device.

@Alexander2010
That is GOOD to know!! Thanks

@lolypop000
These two were missing from update.txt file you pm'ed me. I have added them.
rrgn,48,1:/reg_48.bin
rrgn,148,1:/reg_148.bin

To lost model number on 3490 firmware maybe no much effect to functions.
But it is different if you lost on 3790 firmware.
I got 37xx with less functions. (No 3D Building ability)
I flashed to 3490 and got 34xx but I had 3D Building.

It means to lost model number on other nuvi series may not be a happiness.
Except we test and find no side effects on every nuvi series so ergn,41 is a must thing to do.

Originally Posted by aekhong

To lost model number on 3490 firmware maybe no much effect to functions.
But it is different if you lost on 3790 firmware.
I got 37xx with less functions. (No 3D Building ability)
I flashed to 3490 and got 34xx but I had 3D Building.

It means to lost model number on other nuvi series may not be a happiness.
Except we test and find no side effects on every nuvi series so ergn,41 is a must thing to do.

I know one way to restore model number - apply region 41 from the same model. But in this case will arise one problem - UnitID.
If we will be able to change UnitID in region 41 we will be able to restore model number with no side effect.

Model number - this is only appearance. All functions can be enabled via xml to 37xx. In the earlier models (1xxx, 2x5) model number does not affect the function.