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TTP-243 Pro/ 243E Pro/ 342 Pro
Bar Code Printer
4.8 Black Mark Sensor / Gap Sensor (Receiver) Replacement
Black mark sensor is reflection type sensor. It is connected to JP46 (3 pin connector). A
multi-meter is used to measure the signal of Pin2 to see if there is voltage variation when
black mark is detected. Before conducting the test, please issue the BLINE command first.
The printer will switch from gap sensor to black mark sensor. If there is no voltage
variation, please follow steps below to replace the black mark sensor / gap sensor
(receiver) PCB.
1. Follow the instructions in Section 4.1 to remove all the connectors on mainboard.
2. Take out the mechanism.
3. Remove one flat tap screws and black mark sensor PCB.
Black Mark Sensor and Gap Receiver Sensor
4.Reassemble the removed parts in the reverse order of removal.
