Open Circuit Output Voltage Not Regular; Output Voltage On Resistive Load Operation Not Regular - Cebora 305 Manual De Servicio

ENCODER POWER SUPPLY TEST.
□ Panel board (19), connector J2, terminals 1(+) - 4(-),
voltage = +5 Vdc.
ENCODER TEST.
□ With power source off, temporarily disconnect J2 from
the panel board (19) and check resistance between
terminals of the patch connector disconnected from J2:
− terminals 1 - 4 = terminals 2 - 4 = terminals 3 - 4
= 3 ÷ 5 Mohm approximately.
3.2.7

Open circuit output voltage not regular.

OPEN CIRCUIT OUTPUT VOLTAGE TEST.
□ Output terminals C(+) and D(-) on power source = ap-
proximately +94 Vdc, depending on polarity reverser
position, with start button pressed.
NO Correct?
♦ Regular operation.
BOOST CONVERTER OPERATION TEST.
□ Power board (34), R32 SHUNT(-) terminal (in proxim-
ity of inductor L3) and dissipater DISS2(+), voltage =
+395 Vdc, with power source powered and after start-
up phase, 5 s approximately.
YES Correct?
♦ Check correct fixing and connections
cleaning of the PFC board on power board
(34) J5 connector.
♦ Check the conditions of the boost converter
power components (L3, U5, U7, R32, D11,
D12, C27, C28, C29) on power board (34).
♦ Replace power board (34).
TF5 TRANSFORMER
VOLTAGE TEST.
□ Power board (34), VITE1 terminal(gnd) and R84
terminal (R83 side) = Fig. 5.2.2, open-circuit voltage
on TF5 power transformer secondary side, with start
button pressed.
NO Correct?
♦ Make sure that in the wiring between termi-
nals VITE1 and VITE2 on power board (34),
polarity reverser and power source output
terminals C and D are not short circuits or
3302327/A
YES
NO
SECONDARY CIRCUIT
YES
isolation losses towards ground. If you find
loose connections, tighten and replace any
damaged components.
♦ Check the conditions of the secondary diodes
group (D22 ÷ D29), inductor L7 and the corre-
sponding connections on the power board (34)
printed circuit (for inspection remove the ven-
tilation tunnel on power board (34)).
♦ Check the conditions of the TF5 power trans-
former on power board (34). If you notice
burn signs or deformities, replace it.
♦ Replace power board (34).
■ Check the wiring between J7 power board (34) and J1
panel board (19).
■ Check correct fixing and connections cleaning of the
INV board on power board (34) J4 connector.
■ Check condition of the inverter power components
(U8 ÷ U13, D13, D14, etc.) on power board (34). If you
notice any signs of burns or deformation, replace them.
3.2.8 Output voltage on resistive load operation not
regular.
OPEN CIRCUIT OUTPUT VOLTAGE TEST.
□ Output terminals C(+) and D(-) on power source = ap-
proximately +94 Vdc, depending on polarity reverser
position, with start button pressed.
YES Correct?
♦ Carry out the test in par. 3.2.7.
NOTE
For the following tests use a resistive load capable of with-
standing the maximum power source current. The appro-
priate values are shown in the table.
Resistive
Program load
resistance
E71TGS
0,12 Ω
0.9mm
OUTPUT VOLTAGE ON RESISTIVE LOAD TEST.
□ For this test, set the E71TGS 0.9 mm MIG program in
"2 step" mode:
− press knob B for a time longer than 2 s to enter the
Service Functions menu;
− briefly press the knob B to access the program se-
lection page;
− rotate knob B to select E71TGS 0.9 mm;
− briefly press the knob B to exit the program selec-
tion page;
NO
Power Power
source out- source out-
put current put voltage
180 Adc 23 Vdc
25
EN