Have you tried breaking the lines loose and using the manual syringe to push the fluid through? An air bubble can cause some major lock ups on the HPLC, and are pretty common after part replacements.
Take the line leading from your pump that goes to the autosampler port off and ensure fluid is flowing through it.
Trying to understand the problem here - you say from port 1 you aren’t seeing mobile phase flow to the rest if the system, is that right?
Are you noticing any leaks Anywhere? Especially at the needle seat of the injector?
Did you prime the line with mobile phase once the rotor assemb. was reassembled (did you try to run the pump with dry line)?
Is the purge valve on the pump open?
Have you checked the flow rate when setting the pump at 1 ml/min?
Was the system run prior with any buffered mobile phase?
Are you using the degasser? If so What channels are active?
Could replace the stator face, might not be switching ports very easily. What does your pressure look like when you just run mobile phase with no column attached?