66Chapter 13 TroubleshootingProblem 1: Low reading efficiency.Probable cause What to do:• A target code is not within the scanning range of thereading window.• Bring a code within the scanning range.• The code may be smeared. • Wipe off the dirt from the code.• The code may be blurred. • Use a code clearly printed.Problem 2: Cannot read 2D codes or bar codes.Probable cause What to do:• The type of the code to be scanned has not been setas a readable code.• Specify the type of the code to be scanned as a readablecode.• The scanned bar code contains no check digit, whilethe "Enable, with a check digit" parameter isselected.• Select the "Enable, without a check digit" parameter.• The check digit contained in the scanned bar code iswrong.• Use a correct bar code.Problem 3: Code data cannot be displayed normally on the PC screen.Probable cause What to do:• The communications conditions of the scanner aredifferent from those of the connected host.• Change the communications conditions of the scanner tomatch those of the connected host.