Toshiba DP120F, Service Manual

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March 2000 © TOSHIBA TEC 7-49 DP120F/DP125F Circuit Description
3.16 Paper Jam Detect Circuit
The paper jam detect circuit consists of the I/OP-2 GA (IC48) and other peripheral devices. It
detects the transport status of recording paper by judging the outputs of paper feed sensor
connected to the HVPS and paper exit sensor connected to CN4 on the Mother PBA.
When recording paper is transported by the main motor, paper feed sensor is pushed down by
the recording paper and turns on. This causes the FDS1 signal to be LOW and input to the
I/OP-2 GA to detect that the recording paper is being transported over paper feed sensor.
Then, when the paper is further transported and passes paper feed sensor, the FDS1 signal
goes HIGH. Unless the FDS1 signal goes HIGH within the specified time at this time, the
occurrence of a recording paper jam will be assumed.
When recording paper is transported by the main motor, paper exit sensor is pushed down by
the recording paper and turns on in the same manner as with paper feed sensor. This causes
the FDS2 signal to be LOW and input to the I/OP-2 GA to detect that the recording paper is
being transported over paper exit sensor. Then, when the recording paper is further trans-
ported and passes paper exit sensor, the FDS2 signal goes HIGH. Unless the FDS2 signal
goes HIGH within the specified time at this time, the occurrence of a recording paper jam will be
assumed.
Fig. 7-3-16
07-03-16
Signal Name Type Active Description Destination
FDS1 I L Paper Feed Sensor Detect Signal I/OP-2 GA
FDS2 I L Paper Exit Sensor Detect Signal I/OP-2 GA