Unox MINDMaps BAKERTOP, Service Manual

Page: 209 / 216

Non alarm problems
Symptom problem Solution
The oven does
not turn on
Power board damaged. The
power board does not supply
230 V AC to the primary
transformer
Measure the voltage using a multimeter set to VAC of the P1
soc ke t between the PIN labelled NF and LF of the power
board. If the power board does not provide 230 VAC to the
transformer replace the power board.
Transformer shorted
If the power board supplies 230 V AC to the transformer and
the oven does not turn on replace the transformer.
F2 fuse of the power board
blown
Check if the primary of the transformer is shorted by
measuring the electrical continuity between primary and
secondary turns with the multimeter set to ohm. If the
transformer works properly you should not have electrical
continuity.
■ In case the transformer is damaged, replace it and then
replace the fuse (size: 2A - 250 V type: Fast Acting). Verify
that phase and neutral are not switched;
■ If the primary transformer is fine, replace the power board.
F4 fuse of the power board
blown
F7 fuse blown on the gas
power board
Disconnect the P22 socket, replace the fuse (size: 2A – 250 V type:
Fast Acting) and run the oven (T = 260 °C, t = inf):
■ If the fuse blows again replace the power board, otherwise con-
nect P22 and disconnect the J2 and J3 sockets of the igniter
from the Brahma flame control board and run the oven (T =
260 °C, t = inf).
■ If the fuse blows replace the flame control board, otherwise
at least one of the two igniter is shorted, therefore replace the
double igniters upgrade kit, code XRF011
Gas Power board damaged
Measure the voltage across the P22 socket between the two PINs
labelled ‘NGAS’ and ‘FGAS’ with the multimeter set to VAC:
■ If you do not have power (220-240 V AC) replace the
board;I f you have power (220-240 V AC), measure it
between PIN 8 and 10 of the J5 socket of the Brahma flame
control board with the multimeter set to VAC.
■ If there is no power supply, replace the Brahma flame
control board, otherwise replace the power board.
F9 fuse of the power board
blown
Disconnect the blower from P29 or P27 soc ke t, replace it
and test the oven.
■ If the fuse blows again , replace the power board .
O therwise connect the blower and test the oven
■ If the fuse blows , replace the blower
The ground fault
circuit interrupter
(GFCI) triggered
When you turn on the power
supply the GFCI triggers
immediately
The transformer has an electrical leakage , and needs to be
replaced.
Check the following point s if:
209
Disconnect the low voltage load sockets: P21, P30, P20, P19,
P18, P17, P16, P15, P14, P28, P32, P13, P12 P11, P10, P9, P8 and
replace the fuse (5A – 250V Time Delay), connect the above
sockets one by one until you find the shorted component,
and then replace it. If the fuse continues to blow replace the
power board
Gas ovens
doesn't heat.
The flame icon
is on the display
while the
motors are
normally
running