What are the common signs of a rotted door frame and how can it be repaired or replaced effectively?

Common signs of a rotted door frame include soft or spongy wood, visible mold or mildew, and difficulty closing the door properly. To repair or replace a rotted door frame effectively, you can remove the damaged wood, treat the area with a wood hardener, and then fill in the gaps with wood filler or replace the entire frame if necessary. It is important to address the issue promptly to prevent further damage and ensure the door functions properly.