64UBI EasyCoder 101 – Technical ManualELECTRONICS, cont'd.Potentiometers The CPU-board is fitted with three potentiometers with the follow-ing functions:• WR-1 Display contrast adjustment• WR-2 Label stop sensor (LSS) adjustment• WR-3 Label-taken sensor (LTS) adjustmentAll three potentiometers are easily accessible after the bottom platehas been removed.q Display Contrast Adjustment (WR-1):Using a narrow-tipped screwdriver, turn the screw in eitherdirection until the text in the LCD display on the printer's frontbecomes clearly visible in the prevailing light conditions whenviewed from a normal working position.q Label Stop Sensor Adjustment (WR-2):This potentiometer is used in connection with the printer's SetupMode for adjusting the sensitivity of the label stop sensor. Inmost cases, it will be sufficient to use the adjustment methodoffered by the Setup Mode and the Testfeed facility.q Label-Taken Sensor Adjustment (WR-3):The label-taken sensor (optional) detects if a label has not beenremoved from the outfeed area. Thereby, the printer can beprogrammed not to print any more copies before the last copyhas been removed. The operation of this sensor depends to alarge extent on the reflectivity of the labels (e.g., glossiness,colour etc.). Thus, it may sometimes require adjustment whenswitching between different types of labels.Before changing the setting of a potentiometer, always makesure that the corresponding sensor is clean and free fromobstructions (e.g., pieces of labels or adhesive residue).CAUTION!Since adjustment must be performedwith the power on, take utmost care toavoid any risk of short-circuits.Use non-conductive tools only.Display (WR-1)(hidden)LSS (WR-2)LTS (WR-3)