GD-77 Firmware Update

GD-77 Official firmware v3.2.4 seems to have major problems

I’ve been hearing reports for a few weeks about problems with the ham bands being locked in the latest official Radioddity GD-77 firmware, but I assumed these were isolated incidents possibly caused by problems with the codeplug.

However I received an email this morning from Jason VK7ZJA who has done an analysis of the new firmware and he has concluded that there are potentially quite serious problems with this firmware.

After installing the official firmware version 3.2.4 the ham bands are locked,but it should be possible to unlock them by holding down some keys when the radio is powered on.

A text file that is part of the installation package has the following text in it

Note: Two ways to unlock frequency range
I. Press “SK1” + “7” key to turn on the radio – Press “Menu” to restart
II. Downgrade to old firmware version (before V3.2.1)

However with firmware version 3.2.4 pressing SK1 and 7 does not seem to fix the problem people are encountering, where the radio displays the message “Tx disabled” when the PTT is pressed.

Jason did some analysis of the EEPROM and Flash memory in the radio after firmware 3.2.4 had been installed, and found that the memory locations normally used for the RF calibration data appear to have been overwritten with part of the DMR ID database.

Jason could not find a full copy of the calibration data elsewhere in either the EEPROM or the Flash memory.

If the RF calibration data has been corrupted this is a serious problem, with no perfect way to recover unless the owner of the radio had previously backed up their EEPROM and Flash memory either by using FlashManager or my installing the OpenGD77 firmware and using the backup facility in the Community CPS.

My recommendation would be to NOT update to version 3.2.4


For those who have already updated and potentially partially bricked their radios, there is a potential way to recover the radio by loading someone else’s calibration data into the radio, but since each radio is supposed to have different calibration parameters, this isn’t guaranteed to work.

Also, of course prior to loading someone else’s calibration data the radio should be loaded with an older stable version of the official firmware, for example version 3.1.8

by Roger Clark

Archive of GD-77 firmware uploaded to GitHub

Because Radioddity do not seem to maintain an archive of all the firmware versions that they have released for the GD-77 I have decided to add those files an existing GitHub repository I created some time ago to document various aspects of the GD-77

The firmware file I have copies of, have been uploaded to

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