Hi. So it sounds to me that it passes both self test from what you're describing. The last self test what the unit does is send voltage to the drive motor to make sure the breaks are good. Please recheck the motor. Make sure you have opening from the amateur to the field. Also to the frame. Also remember this if you replace any components like the Q1 and diode and the motor was shorting out you could have taken out the new Q1. There's a simple test to check the Q1 by o17 ramping. On a code 23 I pay a lot of attention to when the code comes on this tells me a lot of where to start. It could be something as simple as a power fuse. But if the code 23 is at the end chances are is you're motor. Loosen the breaks and if the unit kicks the motor and it codes out 23 then your motor is the issue. Code 84 mite come up too but 23 is 1st.