Thread: Garmin GB Discoverer 1:50K - Full Coverage (2.00)

Originally Posted by oracle1207

Hi and thanks to all who replied. I was actually using Firefox and it had worked for all the other segments but not #2. I tried again using Google Chrome and it worked straight off and at a good download speed.

Having got all the parts I now have another problem similar to many people - unlocking it. I have used the Jetmouse Keygen 1.5 with my 1490T unit number XXXXXXXXXX and map id 2043. I would like to have used the sd card id but when I try to get it using the checksum in the service menu I get "0x00000000", which is not accepted by the keygen. This is not a branded sd card, just a 16GB generic. Does anyone have any ideas about unlocking the maps or is there anything I am obviously doing wrong? Both img and unl files are on the sd card in the Map folder. They have both been renamed to "gbdisc50kv2" and there other maps in this folder that do work. Any help would be appreciated.

I'm not sure of how you get the CID by using diagnostics mode on a 1490T. For a nüvi 3790T you will have the 3rd page in diagnostics ""Data Card Test Page" and the "Serial" value. Skip everything about checksum in diagnostics since it's not needed and just takes a lot of vasted time.

Be sure to use JM KG v1.5 with Checksum-fix. Otherwise it will generate wrong keys near 2048=2*2^10 (2043 is close enough and old KGs gives unvalid keys). It should work with [X]:\Map\gbdisc50kv2.img and [X]:\Map\gbdisc50kv2.unl if the key inside the UNL-file is generated with the right KG, UnitID or CID and MapID.

I will send a PM with a 25-char key for your unit.

Hi Ballebar,
Many thanks for the help. I got the PM with the number and have tried it. But again it does not work. One thing I have discovered is that the unlock file is empty after having tried it. I thought I had made a mistake first and not saved it so did it all again. But it seems to be normal that if the unlock code is not valid that it deletes it. I did try checking the number and there was some white space after the number so removed it - but again no luck. I also revisited the sd card using the diagnostics menu. There is a serial number but it is only 5 numbers (62154) and I was under the impression that the instructions on another page here explicitly said this was not the number and it had to be 10 digits. I did try using this 5 digit number in Jetmouse and it did not reject it and generated a number. Unfortunately this code also did not unlock the maps and when I checked afterwards was also missing from the unlock file. I appreciate this is all rather unknown and a bit trial and error, so I am not sure if you have any new ideas? Has anyone actually managed to unlock these maps?