Service manual

CEBORA S.p.A. 13
♦ Make sure the good insulation of the HF generator circuit devices installed on printed circuit
board of power board (29), and remove eventual traces of dirt or powder that can create short
circuits between the devices.
♦ Check the distance between the tips of the discharger SC1 (correct = 0.9 mm.).
♦ Replace power board (29).
3.3.7 - In open circuit operation, the output voltage is not regular.
WARNING
FOR THESE TESTS
DISCONNECT THE HF TRANSFORMER (27) PRIMARY
CIRCUIT TERMINALS FROM “HT” TERMINALS OF POWER BOARD (29), TO
AVOID HF GENERATION
.
OPEN-CIRCUIT OUTPUT VOLTAGE TEST.
 Output terminal – power source (-) and output terminal + power source (+) = voltages per
table:
Process Voltage Condition
TIG +98 Vdc, approx. Start button pressed
MMA +102 Vdc, approx. Power source powered
Correct?
YES
NO
♦ Check the connection between the “NEG” terminal on the power board (29), HF
transformer (27) and - output terminal of the power source, and the connection
between the “POS” terminal of the power board (29) and + power source output
terminal. If you find loose connections, tighten and replace any damaged
terminals.
♦ In TIG make sure start command operation (see par. 3.3.4).
♦ Check the mains voltage conditions and perform test of par. 3.3.1 if necessary.
♦ Replace power board (29).
♦ Regular operation.
3.302.212 12/01/06