Samsung ML-3471ND/XAX Service Manual page 36

Open Heat Error
When the engine operates the warm-up process, if the temperature of the fixing unit is not higher than a specified
temperature, the engine defines Open Heat Error. When this error is broken out, the engine stops all functions and keeps
the error state. Also, the engine informs the error status of the main system. And then the error message is displayed at
LCD window or LED informing the error status of the user.
Low Heat Error
When the engine is at stand-by, printing or warm-up mode, if the temperature of the fixing unit is lower than the specified
temperature at each state and the lower temperature state is maintained during the specified time, the engine defines
Low Heat Error. When this error is broken out, the engine stops all functions and keeps it at the error state. Also the
engine informs the error status of the main system. And then the error message is displayed at LCD window or LED
informing the error status of the user.
Over Heat Error
For overall engine state, if the temperature of the fixing unit is higher than the specified temperature and the temperature
state is kept during the specified time, the engine defines Over Heat Error. When this error is broken out, the engine stops
all functions and keeps it at the error state. Also, the engine informs the error status of the main system. And then the
error message is displayed at LCD window or LED to inform the error status of the user.
* To recover the heat error: The heat error recovery is operated automatically when the error is only caused by Low Heat
Error, not the Heat Errors in Warm-up state and the Over Heat Error. If an error happens, then the engine memorizes a
present temperature. In case of Low Heat Error, the maximum heat is supplied to the fixing unit. When a specified time
is elapsed, the engine detects the temperature again. If the present temperature is higher than the memorized
temperature, the error is recovered. In case of Over Heat Error, no heat is supplied to the fixing unit. When a specified
time is elapsed, the engine detects a present temperature again. If the present temperature is a specified degree lower
than the memorized temperature, the error is recovered.
LSU
LSU receives the image data from PVC or HPVC and make the latent image on OPC surface.
It uses the dual beam, LD1 and LD2. But the control method of them is the same.
Just in comparison with the single beam, the dual beam has the half of lsu s frequency.
->The frequency of the dual beam = the frequency of the single beam /2.
The errors related to LSU are as follows:
* By LReady: When the printing is started, the engine drives the polygon motor of LSU. After the specified time is elapsed,
if the motor is not in a ready status, the engine detects the error that the polygon motor is not in a ready status. If this
error happens, the engine stops all functions and keeps it at the error state. Also, the engine informs the error status of
the main system and the error message is displayed at LCD window to inform the error status of the user.
* By Hsync: When the polygon motor is ready, the LSU sends out the signal called Hsync and used to synchronize with
each image line. So, if the engine does not detect consecutively the signal for a fixed time, it defines the Hsync Error. If
this error happens, the engine stops all functions and keeps it at the error state. Also, the engine informs the error status
of the main system and then the error message is displayed at LCD window to inform the error status of the user.
LSU Error Recovery: If the LReady or Hsync error happens, the paper exits out beforehand. The engine mode is
changed to recovery mode and the engine informs the main system of the engine mode. And the engine checks the LSU
error. If the error doesn t happen, the printing job will be proceeding.
Samsung Electronics
Product specification and feature
Service Manual
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