Hofmann ATC 900 - 6.3 CPU board A1 # EAP0275 G50 A: check and replacement; 6.4 Bead breaker arms potentiometers B1 and B2 # EAA0377 G07 A: check and replacement

CTC-CEN Service Manual 07-13 Rev.E
32
6.3 CPU BOARD A1 # EAP0275G50A: CHECK AND REPLACEMENT
 : 1h
 : Medium cross screwdriver, 5mm allen key, 7mm key, multimeter.
 : Defective processor board may cause the following malfunction:
1. Turning the machine on, the lower bead breaker will not move, the laser pointer will not work.
IMPORTANT! BEFORE STARTING WITH ANY REPLACEMET CHECK CAREFULLY IF ALL WIRES AND
CONNECTORS ARE WELL FITTED AND IF THE FUSE IS FINE.
TO CHECK THE PROCESSOR BOARD A1:
 Turn the machine off.
 Open the electric box.

 Check the fuse, wirings and connectors.
 Turn the machine on
MACHINE UNDER TENSION DANGER
OF ELECTRIC SHOCK
 Take a multimeter and make sure that the board is properly
supplied by the transformer trough connector X2 (red).
 Make sure that there is power output from connector X3 (blue).
TO REPLACE THE PROCESSOR BOARD A1:
 Turn off the machine.
 Disconnect all connectors and wires.
IMPORTANT! DO NOT REMOVE THE CONNECTORS PULLING
FROM THE WIRES. PULL FROM THE CONNECTOR ONLY.
 Remove the 4 screws with the screwdriver.
IMPORTANT! MARK CONNECTORS PROPERLY FOR AN EASY AND SAFE INSTALLATION
 Install the new board.
 Install all connectors and wires.
 Mount the electric box cover.
 Turn the machine on.
 Perform the bead breaker arms calibration.
6.4 BEAD BREAKER ARMS POTENTIOMETERS B1 AND B2 # EAA0377G07A: CHECK AND
REPLACEMENT
 : 1h each one.
 : 4 and 5mm Allen Key, 10 and 13mm end key, medium standard screwdriver, Multimeter.
 : Defective potentiometer may cause the following malfunction:
1. The bead breaker arms are not synchronized.
2. The lower bead breaker arm will not move.
TO CHECK THE 3 TURNS SLAVE POTENTIOMETER:
 Turn the machine off.
 Remove the electric cover.
 Remove the lower potentiometer protection.