GD-77 - CPS/Firmware Loader Can't Find Device

[n3fl]

After three years of sitting on my desk, I decided to convert my GD-77 to Open GD-77. During the firmware upload process, I get the error that it cannot find the device. I know that the USB cable is good (it is a TYT) since it works with my THT TH-350. I tried to use the Radiooddity CPS which was working fine two years ago but now it says it cannot find the device either. I uninstalled that CPS and reinstalled a more current version with the same issues. I encountered the same problems with the MD-UV380 which leads me to believe that something in Windows 10 is blocking the correct driver. The driver shows up as a Prolific USB device in the device manager.
Any suggestions? Thanks.

[F1RMB]

After three years of sitting on my desk, I decided to convert my GD-77 to Open GD-77. During the firmware upload process, I get the error that it cannot find the device. I know that the USB cable is good (it is a TYT) since it works with my THT TH-350. I tried to use the Radiooddity CPS which was working fine two years ago but now it says it cannot find the device either. I uninstalled that CPS and reinstalled a more current version with the same issues. I encountered the same problems with the MD-UV380 which leads me to believe that something in Windows 10 is blocking the correct driver. The driver shows up as a Prolific USB device in the device manager.
Any suggestions? Thanks.

Like using the right cable ?

The GD-77 cable is an empty shell, there is no USB/TTL converter fitted inside.

[n3fl]

Thanks for your response.
I am using the same cable that programs TYT radios including the MD-UV380 which multiple sources online say will work for the GD-77. I have verified that the cable works with the TYT TH-350 so the cable itself is "working". I have also tried the programming cable for the Retevis RT3 which yields the same results.

[F1RMB]

There is no reason that the transceiver is using a prolific driver. Something is definitely wrong here.

[G4EML]

If the cable works with the TH350 then it is the wrong cable for the GD77.

The TH350 uses a serial interface chip in the cable. The GD77 does not.

I would have expected the RT3 cable to work.

[n3fl]

All,
Thanks for your replies. I solved the problem and here is what I did.
1. I used the TYT cable that works with all of the TYT radios that I have which includes the MD-UV380, the MD-430, and the TH-350.
2. I opened the Device Manager (Windows 10) and looked at the USB Com ports. I found that there were two devices named "Prolific". I looked at both of them, one of which said that it was not working. I deleted it, made sure that the radio programming cable was not plugged in and then rebooted the PC.
3. After re-booting the PC, I checked Device Manager again and saw that there were no USB devices attached. I then uninstalled the OenGD77 CPS and re-installed it.
4. After the CPS was re-installed, I plugged the cable into the GD77, turned it on, and then plugged it into the USB port. OpenGD77 found it straightaway and I was able to convert two GD77s and on MD-UV380. The USB Com port now labels the connection as "OpenGD77".


Based on the above, I believe that the bad USB device driver (to which nothing was connected) was preventing the proper drivers from being installed. This problem is analogous to another post that I saw regarding USB drivers issues in the forum. Perhaps someone with more knowledge of the inner workings of Windows can elaborate.

Thanks to all who read and or commented on this thread.

[VK3KYY]

The bootloader in the Radioddity GD-77, enumerates as a USB HID device.

These devices are not easy to see as they are hidden in with the keyboard and mouse devices on a PC

None of the radios that the OpenGD77 firmware supports, uses a serial / Com port for the firmware update



Btw. Did you every run something like Zadig on your PC to swap device drivers, as Zadig can screw up the drivers in the way you described