[billdherup]

This unit just keeps on running.
Seems to defrost but there is some ice that builds on freezer bottom just inside door.

Refrig compartment freezes tomatoes and lettuce at the bottomq

Does not respond to control switch but will turn off manually

Never shuts off on its own but seems to defrost

[denman]

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Replacement parts for General Electric TBX18SIBARWW Refrigerator | AppliancePartsPros.com

This unit just keeps on running.
Seems to defrost but there is some ice that builds on freezer bottom just inside door.
Sounds like you may have a door seal issue.
Take a piece of 2 inch wide paper, place it between the door seal and the frame and then pull it out to check the seal. Work your way around the door.
Also check that the seal on the hinge sides are not grabbing and twisting when the door is closing. IOf it is then a light coat of white lithium grease or vaseline usually fixes this.

Check the freezer temperature it should be between 0 and 5 degrees F.
If lower it could be that the thermostat is shot and the unit can never reach it's set point.
Check the fresh food section temperature it should be around 40 degrees F.
Looks like the amount of cold air that enters the fresh food section is just a mechanical damper so it is highly dependent on the freezer temperature.