The Creality Ender 3 V3 is a consumer FDM 3D printer used for hobby parts, prototypes, and small production runs. Wear is expected: hotends clog, PTFE/heatbreaks degrade, nozzles erode (especially with abrasive filaments), and fans or thermistors fail from heat cycling.
Wiring harnesses and connectors can loosen due to movement, causing intermittent heater or sensor errors. Repairs often make sense because many parts are modular and inexpensive, and a well-tuned machine can remain valuable for years.
Replacement becomes more reasonable when there are repeated electronics faults (mainboard failures), persistent frame/alignment issues, or if you've already replaced major subsystems and still can't maintain print reliability. When comparing to the threshold, include the value of your time: frequent troubleshooting can outweigh the savings of repairing a low-cost printer.