I see this is your second post with this question, so I will copy/paste what I responded on your first post:
The print head should be able to move correctly with the front paper feed tray open, and I just checked ours closely and didn't see how the print head could be blocked. The pizza wheel metal bar is supposed to rise up on it's metal guides, and be just under the bottom of the print head, so the head can still freely move back and forth. I wonder if a part is not positioned correctly? Can you post some photos showing the front paper feed open and closed for me to see the pizza wheel bar in relation to the print head? I'll take a look and let you know if I can see anything obvious, though there's only so much I can help with in regards to printer repair and physical printer troubleshooting.