a. Check Your Power Cord
The problem may not be your computer or your printer at all. Connector cables such as USBs will decay and burn out over time, requiring replacement. Unfortunately, they don’t have indication systems your printer and computer have so that they can die, and you’d never know otherwise. Try swapping your printer out with another cable. Keeping an extra connector cord on hand will help you troubleshoot instantly, and get you printing again faster if your USB is to blame.
b. Ran out of RAM / Memory
Modern printers are highly sophisticated devices. Most units today have some form of memory to store print jobs, whether it be a couple of megabytes or several gigs worth in a large office risograph. If your printer is connecting, but printing at such a slow rate it may as well not be, you’ve likely run out of memory.