The other day I had to have Verizon install a new router and modem. They were only 3 months old, but apparently a recent power outage damaged the router? In any case, my old HP printer won’t get on the new WiFi signal. I’ve tried turning it off and on and even reset it back to factory settings, but no go. It doesn’t like the password?
Is it possible that your new router is only supplying 5ghz connection and your old printer can only connect to 2.4ghz?
If that’s the case, there may be a setting on the router to also set up a 2.4ghz network.
It’s possible. The new router should be just the same as the old one, but I will see if it’s been changed.
That’s exactly what happened in my case, and what I would have asked 
2.4ghz fixed me right up.