Cebora PLASMA PROF 80 Service Manual page 12

CEBORA S.p.A.
source powered. If incorrect, carry out the MAINS CONNECTION TEST in par.
3.3.1. If correct make sure fuse F1 on the power board (20) is intact, and replace
the power board (20) if necessary.
♦ Replace the power board (20).
♦ Replace the transformer (50).
SETTING BOARD (19) POWER SUPPLY TEST.
Setting board (19), connector J2, terminals 3(+) and 2(-) = +15 Vdc and terminals 1(+) and
2(-) = -15 Vdc..
Setting board (19), connector J1, terminal 3(-) and diode D1 cathode (+) = approximately
+22 Vdc; connector J1, terminal 3(-) and diode D13 anode (+) = +5 Vdc.
♦ Check the wiring between J1 of setting board (19) and J3 fuse board (18).
♦ Perform the SERVICES POWER SUPPLY TEST in par. 3.3.1.
♦ With power source off, temporarily disconnect connectors J2 and J7 on setting
board (19) and check the supply voltages again. If correct, identify the connector
causing the malfunction and replace the component to which it is connected
(current transducer (34) or control board (9)). If incorrect replace the setting board
(19).
♦ Replace the control (9) and/or setting (19) boards.
FOR THE FOLLOWING TEST DISCONNECT THE CONNECTOR J4 ON POWER
BOARD (20) TO PREVENT HIGH FREQUENCY FROM BEING GENERATED.
HF COMMAND TEST.
HF board (25), connector J1, terminals 5 and 4 (gnd) = fig. 5.2.1, (HF command pulse), with
start button pressed, for a duration of 2 seconds (maximum pilot arc time).
♦ Check the wiring between J1 of HF board (25) and J8 of setting board (19), being
especially careful to observe the polarity of this connection.
♦ Check the wiring between J7 of setting board (19) (terminal 10) and J1 of control
board (9) (terminal 10) (HF enable signal).
♦ Check on setting board (19), connector J1, terminal 3(-) and R98 (J7 connector
side)(+) (HF enable signal), voltage = +5 Vdc with start button pressed and for a
duration of two seconds (maximum pilot arc time). If correct replace the setting
board (19). If incorrect perform the CONTROL BOARD POWER SUPPLY
TEST (9), par. 3.3.1., and replace control board (9) if necessary.
♦ Make sure that there are no short-circuits between terminals J2 and J3 of HF board (25), and
that there are no short-circuits or interruptions in the connection of the primary circuit of the
HF transformer (23).
♦ Replace HF board (25).
♦ Go to par. 3.3.6.
3.302.167
Correct?
YES
WARNING
Correct?
YES
NO
NO
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25/06/04