HP LaserJet Pro M521 Multifunction Printer series - Manual (Page 207)

Improve fax quality
● Check the scanner glass for dirt and smudges
● Check the send-fax resolution setting
● Check the error correction setting
● Send to a different fax machine
● Clean the pickup rollers and separation pad in the document feeder
● Check the fit-to-page setting
● Check the sender's fax machine
Check the scanner glass for dirt and smudges
Over time, specks of debris might collect on the scanner glass and white plastic backing, which can
affect performance. Use the following procedure to clean the scanner.
1. Press the power button to turn the product off,
and then disconnect the power cable from the
electrical outlet.
2
2. Open the scanner lid.
ENWW Improve fax quality 193