A countertop blender sees high-torque loads (ice, frozen fruit, nut butters), which puts stress on the blade bearings, seals, and drive coupler. The most common practical "repairs" are replacing the blade assembly, jar, lid, or drive socket; true motor or control failures typically make replacement more economical on mid-priced models.
Repair is generally worth it when the base is still strong and the issue is a single consumable component (leaking blade seal, cracked jar, worn coupling) and the total stays well under the threshold. Replace is the better decision if the motor smells hot, stalls under light load, makes grinding noises, or the electronics fail intermittently-those usually indicate core wear.
Frequent heavy blending shortens real-world life, so age matters.