Step 1. The Print Queue
Open the queue on the computer. If there's a stuck job hanging there, delete all jobs, restart the print spooler service, and try again.
Step 2. The Device Itself
Print the configuration page from the device's panel. If it prints, the mechanics are fine and the problem lies in the network or the driver.
Step 3. Network Reachability
Check connectivity to the device using its IP address. No response — look for the problem in the cable, switch, or Wi-Fi. There's a response but no printing — the issue is in the driver or the port.
Step 4. Did the Address Change
The most common cause of "suddenly stopped printing for everyone": the device got a new IP after a router reboot, while the computers still have the old one saved. Assign the address statically, and the problem won't come back.
Step 5. The Driver
After an OS update, the driver may revert to a generic one: printing works, but duplex, tray, and other settings disappear. Reinstall the manufacturer's original driver.
Step 6. The Port
In the printer's properties, check that a TCP/IP port with the correct address is being used, not an old port left over from a previous device.