HP LaserJet Pro M521 Multifunction Printer series - Manual (Page 234)

Solve USB connection problems
If you have connected the product directly to a computer, check the cable.
● Verify that the cable is connected to the computer and to the product.
● Verify that the cable is not longer than 5 m (16.4 ft). Try using a shorter cable.
● Verify that the cable is working correctly by connecting it to another product. Replace the cable if
necessary.
220 Chapter 9 Solve problems ENWW