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Chapter 2   Operation of Diagnostic
Epson AcuLaser C2900N
Revision B
Confidential
4.5.7 Yellow 20% ESS
Outputs the yellow 20% density solid pattern on the whole area of an A4 sheet.
When a PQ problem occurs, this test isolates the problem to the yellow toner or other color toners by 
comparing the print with the sample chart.
Check result: NG (Check the yellow toner.)   OK (Check other color toners.)
4.5.8 Black 20% ESS
Outputs the black 20% density solid pattern on the whole area of an A4 sheet.
When a PQ problem occurs, this test isolates the problem to the black toner or other color toners by 
comparing the print with the sample chart.
Check result: NG (Check the black toner.)   OK (Check other color toners.)