HP DeskJet GT 5820 - Manual (Page 109)

Scan issues
HP Print and Scan
Doctor
The HP Print and Scan Doctor is a utility that will try to diagnose and fix the issue automatically.
NOTE: This utility is only available for Windows operation system.
Solve scan problems Use an HP online troubleshooting wizard
Get step-by-step instructions if you cannot create a scan or if your scans are low quality.
NOTE: The HP Print and Scan Doctor and the HP online troubleshooting wizards may not be available in all
languages.
Tips for copy and scan success on page 54
ENWW Scan issues 103