Jouan B4i - 3.4 Troubleshooting Chart

B4i-M
3 - 6
3.4. TROUBLESHOOTING CHART
Preliminary remark : when a fault is reported, first carry out the appropriate functional test, then refer to the
troubleshooting chart below.
Problem
1) No control active
and no indicator
lights ON.
2) All controls
inoperative. The
display is lit up
without information.
3) Compressor test
incorrect (BR4
i).
4) Lid lock solenoid
test incorrect.
Possible cause
No voltage being applied to the
centrifuge.
Fuses blown (B4
i).
Switching of the line differential
(BR4i).
Short circuit at the power level.
Short circuit on the +5V.
Absence of low voltage on the µP
board.
Faulty display.
Faulty microprocessor board.
Control fault.
Faulty compressor or its
accessories.
Control fault.
Faulty solenoid.
Remedy
Check mains outlet and power cable.
Check for short circuits. Check the absence
of short circuits with an ohm-meter (mains
cable disconnected). Reset the circuit
breaker (replace as required).
Check the insulation between the mains and
the earth of the centrifuge.
Disconnect the mains wires arriving at the µP
p.c.b. If there is still a short circuit at this level
change the µP board or the capacitor.
Check the connections.
Check the presence of +5V on the mother
board with the board disconnected from the
display board. If +5V is present change the
display board. If +5V is absent check the
resistance between the µP board earth and
+5V with the ohm-meter. If the resistance is
zero, change the µP board. If not zero, carry
out the following test.
Check the presence of alternating voltages on
the transformer output.
Check the cables/connectors linking the µP
board to the display card.
Check the cables/connectors to the display.
Check the correct positioning:
- of the EPROM on the µP board
- of the microprocessor on the µP board.
Check the voltage applied to the compressor
terminals. If not apparent or if incorrect,
change the control board. If no effect, change
the mother board. If correct (230 or 120V
according to the version) change the
condenser and/or the compressor start-up
relay. If no effect the compressor coils.
Check the voltage applied to the solenoid
terminals. If not apparent or incorrect (far
from 24VDC) change the mother board or
the transformer.
If the voltage is correct, change the solenoid.