[J STRO]

My upright freezer has been acting strange lately. The display flickers all possible displays while at the same time still shows the temp. clearly. That has been going on for a few months. In the last two weeks, the temp. has been showing 28-58F (sometimes more) this is causing a high temp. alarm to go off. With the unit set on -8 the flickering display could be brought back by resetting the alarm and opening/closing the door. I purchased a freezer manual thermometer and placed it on a shelf and it has been showing -20 unchanging regardless of what the display's showing. The unit seems to run a lot. Only going off for 10 to 15 min. at a time.

[denman]

Here are your parts
Replacement parts for FRIGIDAIRE LFFH21F7HWA FREEZER | AppliancePartsPros.com

Here is the tech sheet
http://manuals.frigidaire.com/prodin.../297246001.pdf

Yes it is running too long as it is trying to maintain a too low temperature.
Freezers should be between 0 and 5 degrees F.

Sounds like the control board is toast since it is flickering.

I cannot find any info on the thermistor so cannot advise you on how to check it. It could cause the low temperature but should not cause the flickering display.

You could try the following but it is a long shot.
Connector Cleaning / Checking
Unplug the unit
Open it up
Remove the ribbon cable from the keypad to the control board at the control board.
Clean the edge connector.
If it is the type where there is not a connector just the insulation is removed, it can be cleaned with a pencil eraser. Do not use an ink eraser as it is too abrasive.
Check the tracks in the ribbon cable for hairline cracks. A magnifying glass helps here.
Would not hurt to clean the connector on the board. Use electronics contact cleaner or isopropyl alcohol and a tooth brush. Be gentle and do not reconnect till all the solvent evaporates.
Reconnect everything and give it a try.

[J STRO]

Replaced control panel tonight, and set temp. to 0* Came back in 45 min. and display shows 46* but inside temp still at -20* High temp. light is on.

[denman]

I did some hunting and found the following thermistor specs.
They are from a fridge so it is a shot in the dark if they are correct but they do look like typical values.

Temperature = Resistance (ohms)
-20 = 166,823
-15 = 138,372
-5 = 99,637
0 = 84,925
+5 = 72592

[J STRO]

Thank you for the quick reply and info. However I'm not sure what to do with it though.
Do you think the thermistor needs to be replaced? I'm looking for the quickest fix before having a house sitter coming in next week so they do not have to deal with it, also I hate to see my electric bill with the unit running near constantly.
Thanks again.

[denman]

The thermistor would be at the top of my list.
Though I would have put money on the control board being the problem.
Who knows perhaps both parts were shot.

The reason I gave the resistance is so you could check the thermistor with a meter to see if it was OK.

[J STRO]

Thanks again for your quick reply. I do appreciate the resistance specs you provided, however I do not have access to a meter.

I am going to try and replace the thermistor. Hope this does it.

Thanks again

[J STRO]

Replaced thermistor freezer working fine.

Thanks for all your help.