The StraPack RQ‑8 Control Box (part 968‑06‑21000) is the main power and logic module for single‑phase strapping machines, housing the motor drive, tensioning electronics, and safety interlocks. Common failure points on this unit include burnt or tripped MOSFETs in the motor driver board, degraded capacitors on the high‑current rail, and worn contactors or relays that control the dual‑tensioning circuit; overheating of the PCB can also trigger the built‑in thermal shutdown. First‑check diagnostics: verify 120 VAC/240 V input voltage and correct polarity at the inlet terminals, inspect the motor drive board for visible burn marks or swollen electrolytic capacitors, and test the relay contacts for continuity and proper operation under load.[oss-gpt-20b]