I have a GE Model TFX25VPBE WW no frost ref and freezer. It is frosting up inside the freezer, and not getting cold in the fresh food section. I believe it's the defrost timer that may be the problem. Where can I locate the defrost timer and the defrost thermostat?

Here's a schematic and parts place that will help you. I use these folks all the time to replace parts.

Freezer section replacement parts for GE TFX25VPBEWW | AppliancePartsPros.com

You can view your entire fridge on this site as well and order any parts you need. Quick shipping also. And a customer service line where real folks answer the phone and help.