It was really hard to properly press two keys at once, thank you for your support …
In short … I tried this procedure (in the manual) :
Insert the SD card to the GXV3240. The SD card should have the valid firmware bin file in it. Power
cycle the phone and the MWI LED will light up. Wait until the MWI LED lights off. Then immediately
press both “*” and “3” keys at the same time for about 8 seconds. MWI LED Release the keys
lights up again. The phone will start the upgrading process.
Note: Before upgrading, please ensure your device is using a 12V power adapter.
It works on one of my other phone but not the one impacted by the problem.
Is there another “fail safe” procedure or solution via tftp?
I have read the manual and I do not see any procedure of this kind.
Thank you in advance to the people who will provide a constructive response