Thread: Enable 3790 features on your 3750/60

turboccc

will you post the tutorial in picture of how you managed to install/solder the new internal mic on a 37xx unit?
and how to disassemble the unit..
i googled for the mic with keywords like "37xx mic, garmin replacement mic, 3790 mic ETC" with no luck, where did you buy yours?

i was playing around with my 3750 last night, flashed it to 34xx, got the voice command function working from webupdater, and now i need to know the difficulty level of installing the mic.. im never good with soldering, hope you can help us in your convenience. thanks

@aiexbadboy,

This is the microphone I used. You can buy it for 3.71$ at DigiKey.

[Only registered and activated users can see links. ]

1- You have to open the unit using a credit card or something thinner. I had a little plastic card half the thickness of a credit card. You have to slide it all around the GPS until it starts to open. Go slowly and take your time.

2- The microphone is just under the antenna (a somewhat orange/rose 1 inch square with a metal plate and a solder dot in the middle. The antenna is soldered on a rectangular green PCB with a long reactangle protuberance. First, there is a screw to remove close to the antenna. Now, you have to pull the PCB, but it sticks to the LCD which is under by the mean of 2 dual face stickers. It sticks very well. Do not pull the PCB too strongly, because I marked mine by doing so. You have to heat the PCB with the antenna with a blower. Once it is hot, the sticker will be less strong and it will let go the PCB more easily. You may want to insert something like a small plastic screwdriver under the PCB to help you pull (gently) the PCB without marking the LCD just under.

Caution: if you damage the LCD in any way, you'll have marks on it when you light it up.

3- The microphone footprint is hidden by a small black tape sticker. Pull it gently and keep it.

4- The microphone is 4 mm by 1.5 mm. It is VERY small. There are 2 pads on it and you need to solder 2 wires #30 (wirewrap) of 1 cm (1/4 inch).

5- The 2 wires must also be soldered on the PCB. The + from the microphone must be soldered in the center of the microphone footprint. The other wire goes on the big circle around the center tap.

6- There are 2 tiny resistor footprint. The one closer to the PCB edge must be either shorted with some solder or you should install a 0402 resistor on it. I made a solder bridge. Much easier.

7- I put the black tape sticker over the 2 solder joints on the PCB trying to hide any metallic are to avoir shorts with the microphone. Because you have to put the microphone in the hole of the top cover of the GPS and put the little antenna PCB where it belongs, I folded the microphone and bended the 2 wires in the middle. This is where the black tape sticker goes into play to prevent any shorts.

8- You are ready to close everything. It is a good idea to test the microphone before you do so.

I'll try to take a few pictures although I would prefer not to go play there again...

A few warnings:

- You may mark your LCD
- The microphone is VERY tiny and the solder pads are VERY small. You need a good soldering iron and some soldering skills.
- The most important part: take your time. It took me one hour because I had no idea what I was doing. I am sure it would take me another 30 minutes to do it on my second GPS. This is not a 5-minute job.

Great info Turbo!!! Hope you make some shots and post them! BTW have a feeling your method could be applicable to other nuvi series where ASR can be enabled but no microphone installed as the one of the upper class. (e.g. nuvi 23xx, 24xx etc. series)

I'm new to this and may ask some stupid questions. I have nuvi 3760LMT and trying to make 3790. Let me explain what I did. I took nuvi37xx_GCDFile__470 (I beleive I can use original GUPDATE file from my GPS, if not let me know) opened it in RGN_Tool ,pached it and saved as .rgn file. I didn't change anything in settings of RGN_Tool, because have no idea what they mean. After that I flashed my GPS with this file by using Garmin Web Updater and nothing happened. What wrong did I do? I also read I need .srd files to make voice recognition working, I beleive, I also need some files to make 3D working. Where should I get them?

Thank you.

I am new here. I like to share that my 3760 us firmware 4.70(bought from a friend) succesfully flashed and now can use voice command. The detail instructions on page 8 help me a lot.
To ivan2red, you have to use updater.exe in post #79 not web updater. After flashing then use web updater to get voice recognition file.
Hope this help.

Yes you can use your gupdate.gcd to to modify,3D file you find here:

[Only registered and activated users can see links. ]