Microwave oven query

[Syke]

I have a Panasonic combination oven (NNA850) about three years old.
Recently, I suspected that when I was using it on convection (fan) only,
the food was a little undercooked. I obtained an oven thermometer and
placed it on the turntable. I then selected 200 celsius on the LED panel
and when the warning sound came, the oven thermometer read only 160
degrees. It was consistently achieving 40 degrees under at other
temperatures as well. I took it to an approved repairer who replaced the
thyristor. When I got it back I tested it and got the same result as
before. I tried the thermometer in my conventional fan oven and the temps
were fairly close to what I selected.

Am I missing something here?

Regards and thanks in advance


Pat Macguire

 

[Paul Brooks]

I have a Panasonic combination oven (NNA850) about three years old.
Recently, I suspected that when I was using it on convection (fan) only,
the food was a little undercooked. I obtained an oven thermometer and
placed it on the turntable. I then selected 200 celsius on the LED panel
and when the warning sound came, the oven thermometer read only 160
degrees. It was consistently achieving 40 degrees under at other
temperatures as well. I took it to an approved repairer who replaced the
thyristor. When I got it back I tested it and got the same result as
before. I tried the thermometer in my conventional fan oven and the temps
were fairly close to what I selected.

Am I missing something here?

Regards and thanks in advance


Pat Macguire

Another favourite problem is where the air dampers don't close. When the
oven is used in convection mode then the air is recirculated inside the oven
and it then gets hotter and hotter - if there is an air leak then the hot
air can escape from the oven cavity which can cause a lower temperature in
the oven. Generally the oven temperature should be +/- 10% of the rated
amount given on the display.
The above fault is normally a progressive one but we find quite often that
customers don't realise it until it is typically about 25 % lower than the
display temperature.
If it is a UK Nat Pan Repair Centre then take it back as it will be under a
90 Day Service Warranty and it is their mistake for incorrectly diagnosing
the fault.

Paul

 

[[email protected]]

I have a Panasonic combination oven (NNA850) about three years old.
Recently, I suspected that when I was using it on convection (fan) only,
the food was a little undercooked. I obtained an oven thermometer and
placed it on the turntable. I then selected 200 celsius on the LED panel
and when the warning sound came, the oven thermometer read only 160
degrees. It was consistently achieving 40 degrees under at other
temperatures as well. I took it to an approved repairer who replaced the
thyristor. When I got it back I tested it and got the same result as
before. I tried the thermometer in my conventional fan oven and the temps
were fairly close to what I selected.

Am I missing something here?

Yes, you replace the thermostat, not the thyristor. Also it's not
a good idea, nor will it give accurate results, if you microwave a
thermometer, but it's ok for testing in convector mode.

 

[Sam Goldwasser]

I have a Panasonic combination oven (NNA850) about three years old.
Recently, I suspected that when I was using it on convection (fan) only,
the food was a little undercooked. I obtained an oven thermometer and
placed it on the turntable. I then selected 200 celsius on the LED panel
and when the warning sound came, the oven thermometer read only 160
degrees. It was consistently achieving 40 degrees under at other
temperatures as well. I took it to an approved repairer who replaced the
thyristor. When I got it back I tested it and got the same result as
before. I tried the thermometer in my conventional fan oven and the temps
were fairly close to what I selected.

Thyristor or thermistor?

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

 

[Paul Brooks]

Thyristor or thermistor?

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

I wasn't going to nitpick on that subject as it would only confuse the
originator of the message ( and probably the "very skilled NVQ Technician" )

Paul

 

[[email protected]]

I have a Panasonic combination oven (NNA850) about three years old.
Recently, I suspected that when I was using it on convection (fan) only,
the food was a little undercooked. I obtained an oven thermometer and
placed it on the turntable. I then selected 200 celsius on the LED panel
and when the warning sound came, the oven thermometer read only 160
degrees. It was consistently achieving 40 degrees under at other
temperatures as well. I took it to an approved repairer who replaced the
thyristor. When I got it back I tested it and got the same result as
before. I tried the thermometer in my conventional fan oven and the temps
were fairly close to what I selected.

Am I missing something here?

the need to take it back and insist they fix it properly?