Main Control Board; Precautions For Replacing The Main Board; Checking Voltage Levels; Led Status - GRAPHTEC CS2000 Service Manual

9.3 Main Control Board

1. Precautions for replacing the main board

(1) Before replacing the main board, note the feed correction value, X overlaps and Y offsets values currently
selected for the scanner, if these values can be checked. (To check these values, follow the procedure
given in "Preparations before Making Adjustments" in Section 10.2 on p. 10-3.)
(2) Use Scanning Master 21+ to make adjustments.

2. Checking voltage levels

(1) Remove the bottom cover.
(2) You will find test pins (TP1 through TP6) in the lower left corner of the main control board. The output
voltage levels of these pins are given below:
Test pin
No. Name
TP1 GND
TP2 +24V
TP3 +5V
Tp4 VCC
TP5,6 +2.5V

3. LED status

An LED is provided on the main control board.
U5: Red when the CPU is running.
U5: Remains unlit when the CPU is not running (when an error occurs).

4. Replacing the main board

(1) Before replacing the main board, note the feed correction value, X overlaps and Y offsets values currently
selected for the scanner, if these values can be checked. (To check these values, follow the steps given
in "Preparations before Making Adjustments" in Section 10.2 on p. 10-3.)
(2) Remove the bottom cover and disconnect all cables from the main control board.
(3) Remove the six screws securing the main control board.
(See "Main Board" in Section 8.9 on p. 8-10.)
(4) Detach the SDRAM from the P4 connector and install on the new main board.
(5) Attach the new main board by reversing the sequence of steps in which the old board was removed.
(6) Initialize offset by setting DIP switch 2 on the scanner unit to the ON position; then turn ON power while
pressing and holding the STOP key.
(7) Perform Calibration (white correction). (See "Calibration (white correction)" on p. 10-5.)
(8) Adjust the feed distance. (See "Adjusting feed distance" on p. 10-6.)
CS2000-UM-251-9370
Output voltage
+0V
+24V
+5V
+3.3V
+2.5V
9-5
9. BOARDS AND ELECTRICAL COMPONENTS
Perimssible range
+23.5V to +24.5V
+4.9V to +5.1V
+3.25V to +3.35V
+2.4V to +2.6V