Excellent.
Also Excellent.
Not right.
But this confirms that you've probably assembled everything correctly.
It remains to be clarified whether your computer has an active power function from the USB port.
It would also be a good idea to try out a different power supply for your printer. Yes for testing.
I am currently watching the diagram and images of your controller board. I don't know to what extent these materials are up to date.
I mean switching off the mechanism that activates switching the 5V power supply to the logic in your controller (between PSU and USB). This can help solve the problem.