"CAUTION . . . Both Axes - No response" - multiple SkyWatcher mounts and 2 hand controllers!

[CaptainTweaky]

Hand controller message immediately after 'Intitializing' - "CAUTION . . . Both Axes - No response"

I have SkyWatcher EQ6-R Pro, new AZ-EQ5GT and AZ-GTi mounts. If I use the hand controller from the EQ6, all three give the above message. So a fault with the hand controller you might think! If I use the hand controller that came with the AZ-EQ5GT, it works perfectly with its own mount, BUT when plugged into the AZ-GTi with the correct cable (that used to work perfectly well), I get the above message. So that would suggest it's not the EQ6-R hand controller, it's the mount!! Hmmm - now that's some coincidence, both failing at the same time with the same fault!

I have updated the firmware so both hand controllers are, in theory, exactly the same. I have updated the AZ-GTi firmware and cleaned ALL the contacts and used different cables on all mounts, but the problem is completely consistent. The AZ-GTi and the EQ6-R work perfectly well when either tablet controlled or computer controlled respectively.

Personally I prefer to use a hand controller for the AZ-GTi because you can feel you're pressing the correct direction buttons, it's not necessary to look at the screen. But more than that, I'd really like to know what on earth is going on.

Has anyone else encountered this exact same problem or very similar? Does anyone have any idea what can be causing such a coincidental error? Any help would be greatly appreciated.

[malc-c]

The "no response" message simply means the handset doesn't get an acknowledgement back when the handset sends the commands to the motorboard in the mount to enquire what firmware (and mount) it is communicating with.  The cause can be several things.  The speed of the serial communication may be different (the default is 9600, but some mounts operate at 115200, especially through a direct USB connection to a PC for example ).  It can be a fault in the cable, or which often seems the case, the Processors on the motor board are damaged, often through connecting either the wrong serial adapter / USB cable, or connection of the handset to the wrong port.  It may be that your swapping handsets around has blown the UARTS on the micro controllers in the mounts.  

Have a read of This long thread which covers the repair of selected motor boards that use PIC 16F886's  

However, you state that the two affected mounts work fine when connected to a PC, which would suggest that the processors are fine, which is the confusing part.  How are you making that connection, via USB or through an EQDIR cable ?