The Coats Wheel Balancer Model 1004 (part 304512) is a computer‑controlled balancing system that uses an electronic display panel to show load data and balance calculations. Common failure modes for this class of units include degraded power‑supply modules, blown fuses or tripped circuit breakers in the control board, faulty LCD/LED backlight circuits, and worn or misaligned wheel‑sensor contacts on the drive shaft. Additionally, motor drives can fail due to overheating or capacitor discharge, leading to erratic speed control or no movement of the balancing head. First‑check steps: verify mains voltage and ensure all fuses are intact; inspect the display board for burn marks or loose connectors; review any error codes shown on the panel and cross‑reference with the service manual’s diagnostic chart.[oss-gpt-20b]