Cebora 965, Service Manual, Page: 12 / 24

CEBORA S.p.A.
12
3.3.5 - Gas flows from the torch, the pilot arc does not light (high frequency missing).
HF OSCILLATOR TEST.
Correct?
‰
Control board (6), discharger SCI1 discharges at regular intervals, for approximately 300
msec. (HF generation time) with start button pressed.
NO
YES
♦
Check wiring between HF transformer (31) and terminals J5 and J6 of control
board (6). More specifically, make sure the primary winding circuit is not
interrupted or in short-circuit. If necessary fix the connection or replace control
board (6) or HF transformer (31).
♦
Check connection of the HF transformer (31) secondary winding with rectifier
(32) negative terminal and torch cable electrode terminal. If you find loose
connections, tighten them and replace any components with damaged terminals.
♦
Check the condition of the torch cable and torch; especially make sure there are
no short-circuits or insulation leaks between the conductors, and that electrode,
nozzle, nozzle holder and diffuser are not to be replaced (see Instruction Manual).
♦
Make sure that the gas pressure in the torch plasma chamber is not too high. If
necessary check operation of the pressure regulator (E) and pressure gauge (F)
and adjust in observance of the technical specifications.
♦
Go to par. 3.3.6.
♦
Check the distance between the tips of the discharger SCI1 (correct value = 0.85 mm.).
♦
Check the wiring between J10 of control board (6) and rectifier (32) (+) and (-) terminals.
♦
Make sure the power source output voltage presence, performing if necessary tests of par.
3.3.6.
♦
Make sure the start command working condition, performing if necessary START
COMMAND TEST, par. 3.3.3.
♦
Replace control board (6).
♦
Replace HF transformer (31).
3.302.173 28/07/04