Epson Perfection 640U Series, Service Manual

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EPSON Perfection 640U Revision A
Troubleshooting Overview 20
3.1 Overview
This chapter describes troubleshooting procedures for this scanner.
3.2 Self-Diagnostic Function
The self-diagnostic function of the scanner lets the scanner itself detect
abnormal conditions. When the scanner detects an abnormality, it
shows an error using the lamp. See Table 3-1 for the errors detected by
the self-diagnostic function.
Table 3-1. Errors Detected by the Self-Diagnostic Function
Lamp Condition Error Type (Cause Remedy)
Red LED lighting up Command Error
Cause: Undefined command or undefined command
parameter is received.
Disposition: The scanner ignores the wrong command or
parameter, ( Maintain at current settings.)
Scanner sends NACK, and waits for the next
command or parameter.
Remedy: Once the correct command is received, the error
condition is cleared.
Red LED High
speed blinking
(Goes off after 30
minutes.)
Interface Error
Cause: Detects the wrong action in the communication
procedure.
Disposition: Lamp goes off and scanner stops operating.
Remedy: ! Turn power off and then turn it on again.
! Plug out and in the USB connector.
Acceptable command: None
Red LED High
speed blinking
(=the lamp has
blown out.)
Blinking
(=error except the
lamp has blown
out.)
Fatal Error
Cause: ! Lamp is broken.
! Power is turned on or command is received
without removing the transportation lock.
! Scanner unit fault.
Disposition: ! Lamp goes off and the scanner stops
operating.
! The bit 7 of the status byte is set.
Remedy: ( After cause is remove )
! Switch off the power and turn it on again.
! Send initialization command (ESC @).
! Plug out and in the USB connector.
Acceptable command: [ESC F, ESC f, ESC @]