I just installed a new 1Tb hard drive in my MacBook Pro (2.2 GHz Intel Core i7, early 2011). Installed Snow Leopard as it was the only system disk I had, then brought everything back over from my Time Machine backup, then upgraded back to Mavericks, which is what I was running before. I have an old beast HP Laserjet 5000N, which has been running perfectly fine attached with an ethernet cable to my MacBook, as an IP printer. IP address is 18.104.22.168 It worked fine with Mavericks with the previous hard drive, but now my MacBook won't find it. It comes up with the message "Unable to verify the printer on your network." If I try to add the printer anyway, it just gets hung up. Nothing appears on the little screen on the printer itself. I've tried adding it again, reset the printing system, restarted everything, used a different ethernet cable, no luck. Do you think it would help to buy an Airport Express, or would that just be a waste of money? Advice?