[JBicky]

Hey guys,

We have a 3 year old Frigidaire electric oven model FPMC2785KFA that we started having issues with about 6 months ago.

I've done some minor troubleshooting listed below. I'm not sure what I should do further. I was thinking about buying a new circuit board but I figured I'd post here before forking over the dough.

Thanks!

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Symptom:

You turn it on Powerplus PreHeat. After a few minutes it beeps alerting that it hit the correct temp (450 for example), but the oven thermometer we put inside will only be around 200. If you turn it off, then hit Bake and re-type in the 450 and it will show about 220 on the display, and will start to heat up again.

When it does hit 450, it will beep stating its at 450, and will be at 450 briefly but over time that temperature will drop again without any indication that its failing. If you hit Bake again, the temperature on the display will read whatever the real temp is (for example: 400), and it will kick the fan on and heat back up to 450.
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Troubleshooting done so far:

It sounds like a computer issue to me. I don't believe its a heating element issue, otherwise the oven would never display incorrect temperatures. I feel like its not a thermocouple issue because it will accurately display the real temp every time "Bake" is turned on and the temp is re-entered.

I've turned the breaker off and left it off for 10 minutes to reset the computer. Turned it back on and it repeats the same issues.

I've unscrewed the thermocouple probe to inspect it. Its got a long cable connected to it with heating insulation around it. I can't inspect the connection because its crimped inside the probe and the heat insulation goes inside.

For kicks I also inspected the connectors on the heating element and they look fine.
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Thanks for the help guys! Much appreciated! Been reading articles on this forum for a while but never asked anything.

[denman]

Here are your parts
Parts for Frigidaire FPMC2785KFA Wall Oven - AppliancePartsPros.com

You have done a pretty thorough job of troubleshooting and I agree with you that it is probably the control board.

I would check a couple things before getting a replacement board.

Check the connection of the probe on the board.
Check that the pins are clean and that the crimps to the wires are good.
Check for a cold solder joint on the back of the board to the probe connection. Cold solder joints are often a duller silver color and/or may have pin holes.
Wiggle the connector while looking at the solder side to see if the connection pins move in the solder.
Check for any hairline cracks across the copper trails on the board.
A magnifying glass comes in handy when checking the solder side of the board.

If all OK then I would replace the board.

[JBicky]

Thanks for the response! Much appreciated.

I'm seeing there are two controllers. One is the Control Board (Main Circuit Board I'm assuming) and one is the Controller. I'm assuming the Controller is just the Input/Output interface?

Thanks again! I'll check on the control board tonight.

[denman]

As far as I know one controls the oven and the other controls the microwave.

Below is the wiring diagram for the oven part.
http://manuals.frigidaire.com/prodin.../318046267.pdf