ProtoTRAK M2 is a two‑axis CNC controller with an integrated digital readout (DRO) that drives servo motors and displays position data on a small LCD panel. Common failure modes include power‑supply voltage drops causing the DRO to flicker or reset, I/O bus errors leading to “comm error” codes, and overheating of the main PCB due to inadequate ventilation or dust buildup. First‑check steps are: verify 24 V DC supply rails with a multimeter, inspect all ribbon cables for loose connections or broken traces, and review the controller’s diagnostic log for any error codes (e.g., “PWR‑FAIL”, “COMM‑ERR”). If the DRO remains unresponsive after these checks, perform a visual inspection of the PCB for burnt components or solder bridges.[oss-gpt-20b]