Thread: Firmware downgrade for 721xs to recognize custom maps

Thanks Neil!

I found v3.60 on my one backup but struggling to get it to see my maps =(
If I use the unmodified map its says maps are locked then I unlock then it does not detect the maps
Have tried Garmin unlocker alternative 7.16 and 8 no joy

Not sure if I did the factory reset before or after the downgrade which might be the cause perhaps?
And seeing that it detects the locked map on the sd card the FAT32 formatted 8GB card is working fine?

Will version 4.2 allow custom maps still?

Sorry for all the questions and thanks for the help

Edit:

Sorted thanks!

Did factory reset
Reloaded v3.6
Removed Card
Factory Reset
Copied latest copied of maps to card
Used gimgtools-0.02-win32 to unlock
Opened Garmin Homeport
Deleted untitled.adm via Homeport
Exported waypoints
Insert into Garmin and powered on

Working like a charm thanks this website contains a lot of great info

Hi,

I have a Garmin GPSMap-741xs and I cannot read Custom Maps on it. I tried to download ChartPlotters_FW_09Sept2014.rar]ChartPlotters_FW_09Sept2014.rar from the links provided on this thread, but they no longer work (deleted by owner?). Can anyone supply a new link where I can download this firmware?

Hi Neil,

I have a Garmin GPSMAP 741xs plotter and want to downgrade the firmware to restore custom maps. Your link no longer works (deleted by owner).
Do you still have the firmware file, and if so, how can I get it from you?

kevinvh

You can download previous firmwares from here:

Code:

Please Login or Register to see the links

{Thanks to Vlasto1 from the Rusfishing forum for this link.}

I do not know the exact HWID of 741xs, but I guess that it is one of 1665/1666/1667/1668.

Code:

Please Login or Register to see the links

@kevinvh

The GPSMAP® 741xs is a legacy device and its firmware does not contain the new piracy protection.
This unit will support custom maps if you process such maps with a GCCMaps0.0.3 patcher!

Do you mean that custom maps will work with the current firmware so long as they are created with GSSMaps0.0.3 patcher?

@kevinvh
What's written in Post #28 is exactly what's meant, "processed" not "created" i.e. existing custom maps such as OpenSeaMaps are treated so they become usable in the device. You will need to search for GCCMapsPatch0.0.3 (which is short for 'Garmin Chartplotter's Custom Maps Patch Version 0.0.3') as it's not allowed here now due to changes to forum rules, some years back.

Hello,

Garmin now had blocked the possibility of installing old firmware in some devices if not all of them.

I learnt it yesterday when i installed version 6.80 in my garmin 721 and i lost the possibility of returning to any other firmware. Holding the button now does not work now, it worked in 6.5 or any other old firmware. I have done it before from 6.5 to whatever firmware i liked for example 2.8. But now Garmin 721 does not offer the possibility of installing old firmware. Garmin has blocked it to not allow the use of other maps made by third party sources. In my case it was a local map made by an individual for a very small 10kmx10km area.

Is there any way to get rid of an installed 6.8 version and return to old firmwares?

Could somebody help me finding firmware 3.8 and 4.2 for 721 for my other unit?

Any help will be appreciated. I have only 2.8 old firmware and modern ones.

@ferabella

For the GPSMAP 721 unit, there is no point in going back to the old firmware, just patching your custom map with GCCMaps0.0.3 is enough.