Panasonic NB-G110PLVA, Service Manual

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5.3. Operation check test for the heater and thermistor
The precondition for this test is to set the baked color to "Medium".
5.4. TABLE OF TROUBLESHOOTING GUIDE
When performing the troubleshooting, see the check point on page XX for the electric resistances of the parts which might cause
any trouble.
Notes:
When the power is supplied to the algon heater, it is too bright to visually check the upper heater assy. (far infrared rays heater)
and the lower heater assy. (miracron heater) for malfunction or breakage of wire. If the consumption power cannotbe mea-
sured, turn off the heater and visually check the dim light of the upper and lower heaters.
Note:
The unit is controlled with both of the power board and the operation board on the P.C. board unit. Replace the P.C. board unit
as a set.
No. Operation Working description Items to be checked
Display and buzzer information Action
1 • Connect the power cord to the
120 V a.c outlet.
• The power lamp comes on. • Check the power cord
2 • The power supply button is
pushed.
• Power supply indication light light-
ing.
• The power cord is normal.
3 • Press the "Toast" key. • The "Toast" lamp comes on.
• The cooking time display "2.5 min."
blinks.
• The cooking time display comes to
"0 min."
• The buzzer sounds 12 times.
• Only the power lamp comes on.
* The heater is heated up
to become red.
• The heater turns off.
• Check the algon heater.
* The upper heater has no failure.
* The lower heater has no failure.
4 Disconnect the power cord from the outlet (to carry out the check test for the thermistor).
5 • After 10 sec., make sure that
the power button is set to "ON".
Then, connect the power cord
to the 120 V a.c outlet with the
temperature control "
" and
the timer " " keys pressed.
(test mode)
• The power lamp comes on.
• "Vin a.c oder" on the timer display
blink in this order repeatedly.
Check if the mode changes to the
test one.
* The mode change was ended in
failure.
(Perform the operation of No.4
again.)
6 • Press the " " key of the
"Shade Control".
• The power lamp comes on.
• The buzzer sounds once when the
key is operated.
• The temperature lamp "500"
comes on.
• The thermistor has no failure.
7 After checking, press the power button to finish the test.
Troubles Items to be checked Remedy
Power cannot be supplied.
• Power cannot be supplied to all heaters.
• Power cannot be supplied to all lamps, too. • Check the power cord for breakage.
• Check the P.C. board for correct connection • Replace the power cord.
• Replace the P.C. board.
Baked color won't be added to the food upper sur-
face
• The algon heater won't emit light.
Measure voltage
• 120 V a.c is sent to CN2 and CN6.
• 120 V a.c is not sent to CN2 and CN6. • Replace the algon heater
• Replace the P.C. board
Baked color won't be added to the food upper sur-
face
• Power won't be supplied to the upper heater
(far infrared rays heater).
Measure resistance
• Measure upper heater resistance: approx. 31
Ω
• Measure upper heater resistance: None
• Replace the P.C. board
• Replace the upper heater.
Baked color won't be added to the food lower sur-
face
• Power won't be supplied to the lower heater
(miracron).
Measure resistance
• Measure upper heater resistance: approx. 26
Ω
• Measure upper heater resistance: None
• Replace the P.C. board
• Replace the lower heater.
No switch except the power switch will be accepted.
• "H1" is displayed and the toast lamp blinks.
Measure resistance.
• Measure thermistor resistance: approx. 1.4M
Ω
or
more (Thermistor is broken or short-circuited.)
• Replace the thermistor.
Power is supplied to the algon heater for 5 seconds
after cooking starts. After that, no power is supplied
to the all heaters. • The thermistor is short-circuited. • Replace the thermistor.
No keys on the operation area is accepted.
• Baked color cannot be controlled.
• Cooking key cannot be operated.
• The LED lamp won't come on.
Check the P.C. board.
• Terminals on the P.C. board are not connected.
• The P.C. board is cracked.
• The electronic parts are broken. • Connect the terminals correctly
• Replace the P.C. board.
• Replace the P.C. board.