Toshiba E-STUDIO520, Service Manual, Page: 400 / 592

e-STUDIO520/600/720/850 TROUBLESHOOTING March 2005 © TOSHIBA TEC
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(e-STUDIO520,e-STUDIO600,e-STUDIO720)
1) Check if the connector CN209 on the PLG board is about to be dis-
connected.
2) Check if the harness is about to be open circuited and the connector
pin is disconnected.
3) Check if the following signals are transmitted on the pins of the con-
nector CN209 on the PLG board.
Pin 1: 27±1V, Pin 2: GND, Pin 3: Less than or equal to 1V (Lo),
Pin 4: Less than or equal to 0.7 V (Lo), Pin 5: Do not touch.
4) Check if the conductor pattern on the PLG board is short circuited or
open circuited.
5) Check if the laser unit cooling fan is not stopped.
6) Check if the intake area of the laser unit cooling fan is not blocked.
7) Replace the laser optical unit.
8) Replace the PLG board.
(e-STUDIO850)
1) Check if the connector CN206 on the PLG board is about to be dis-
connected.
2) Check if the harness is about to be open circuited and the connector
pin is disconnected.
3) Check if the following signals are transmitted on the pins of the con-
nector CN206 on the PLG board.
Pin 1: 27±1V, Pin 2: GND, Pin 3: Less than or equal to 1V (Lo),
Pin 4: Less than or equal to 0.7 V (Lo), Pin 5: Do not touch.
4) Check if the conductor pattern on the PLG board is short circuited or
open circuited.
5) Check if the laser unit cooling fan is not stopped.
6) Check if the intake area of the laser unit cooling fan is not blocked.
7) Replace the laser optical unit.
8) Replace the PLG board.
YES
1) Check if the conductor pattern on the PLG board is short circuited or open circuited.
2) Check if the grounding wire of the high-voltage unit (e.g. developer unit, transfer unit) is
grounded securely.
3) Check if the bias contact point of the high-voltage unit is contacted securely. (Check if
the point is not stained either.)
4) Check if the metal plates of the transport system are grounded securely.
5) Check if the equipment is grounded securely?
6) Check if the laser unit cooling fan is not stopped.
7) Check if the intake area of the laser unit cooling fan is not blocked.
8) Replace the laser optical unit.