I had a router problem just last week which meant that my printer could no longer connect to it. Fortunately it was dead easy to fix, so hopefully it will be the same for you. (However I can't give you
precise instructions because you've not provided the make and model of either your printer or photocopier).
Any new router almost certainly has a 'WPS' button on it. If it's not actually labelled 'WPS' then it's likely to have a symbol somewhat similar to a 'recycling' one (
http://blog.dlink.com/wp-content/uploads/2011/07/wps.jpg ) or a 'transmitter' symbol (
http://bt.custhelp.com/rnt/rnw/img/enduser/bt_wps_step3.png ).
You need to hold down the WPS button on the router for 5 seconds, release it and then, quickly afterwards, press the corresponding button on your printer. (Then repeat for any other device which needs to be connected to the router).
Some printers (and other devices) have a dedicated 'WPS' button but on others (including mine) you need to go into the menu settings to turn a particular button into the WPS one. Please ell us the make and model of the printer (and of any other relevant devices) if you need help here.