In an earlier post from the original thread where you first mentioned your tank, you also mentioned, "it has the push button controller", but now you say, "pushed forward on the joystick"?

This is confusing details. The push button controller has no joystick. So to clear things up, do you have the push button controller, or the joystick style controller?

Also, if the left motor was working normally before, & you hook the right motor to the left port & the motor itself is OK when tested, then it makes sense the motor isn't an issue. But this test doesn't tell you that the Tx is truly working properly or not.

So I'm not saying it isn't a tank PCB problem, because it certainly could be, but if you are having issues with just one side control, it can still be the Tx causing that issue with the way the contacts might be working, or in this case, might not working, or just a loose wire or plug in the Tx.

All you seemed to have ruled out is that both motors spin in both directions, & the gearbox seems to spin freely on both sides in both directions too, & since I haven't read anything you have done exclusively to test the Tx to rule it totally out as having no issues, I'm not sure why you still only want to focus entirely on the tank board as the only possible cause.

In my opinion, to do the full proper trouble shooting, I still suggest strongly that you take the Tx apart & check the internal plugs & connections, as well as that the contact pads are free from having any debris between them & the contact points on the board, & they are properly positioned where they should be. This is actually very easy to do, & at least an inspection might reveal something that is causing your issue. Even if everything inside looks OK too, at least that's one more trouble shooting step which really needed to be done, out of the way.

~ Craig ~