Epson DFX-9000 Service Manual page 69

Epson DFX-9000
2.2.2.1 Carrier mechanism error detection
There are two error detection methods for the Carrier drive mechanism:
SP motor out-of-step error
The stop positions are calibrated during the Carrier unit positioning
initialization in order to prevent stop-position variations caused by
mechanical load or SP motor variations. The Left Edge sensor (LES)
corrects the deceleration-start position after measuring the gap between
the actual and predetermined stop positions. If the gap is bigger than the
allowable correction value, the SP motor is determined to be out of step,
resulting in a fatal error. (
fatal error: LES error
the following conditions:
When the LE sensor cannot detect the Shield plate though it is in
position to do so.
When the LE sensor detects the Shield plate when the sensor is not
in position to do so.
The out-of-step detection is not carried out each carriage pass. It is
performed whenever the Carrier unit passes over the Shield Plate while
printing or during other normal carriage operations.
CR motor driver error
The CR motor driver error (
fatal error: CR driver error
following conditions:
When a damaged SP motor, or defective SP motor driver, causes an
abnormal electric current.
When a single phase of the SP motor is live with electricity for an
abnormal period of time.
The +42 V power supply hardware is shut off when this error is detected.
Operating Principles
). The error occurs under
) occurs under the
Printer mechanism
2.2.2.2 SP motor thermal protection control (with built-in
thermistor)
To prevent the SP motor from burning out, if the SP motor temperature
rises above a preset threshold, printing operations are modified to
include a one-second pause at the end of each print pass. This is repeated
for five passes, and the temperature is evaluated again. Normal printing
resumes once the temperature drops into normal operating range.
Revision B
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