HP 1312 printer running wirelessly from a laptop (Windows 7). Has always worked fine. Turned printer off when we were on vacation; now printer is "offline." Have reinstalled printer driver and...
The problem you described can have multiple causes.
But one is more common:
Every device on your home network (wired or wireless) has its own IP adress. Usualy this IP adress is given automatically by the DHCP server contained in your wireless router. When a device is turned off for some time, it can receive when turned on again another IP adress than before.
So, if your printer has no static IP adress (entered by yourself during printer setup), it is very likely that it has now other IP than the address known by your computer. The computer sends the print jobs to the old adress and of course, nothing is printed.
Please check in your printers proprieties the adress of the TCPIP port assigned tom it, and also check on your router's management site what clients are connected to it.
The network communication between the computer and the printer can be checked by issuing a PING command from a command prompt.
e.g ping 192.168.1.***
the numbers are one example of an IP adress.
Please let me know if it helped, if you need more help ask again, I'll be glad to help you to get the problem solved.