Spectra‑Physics 1042 Laser Level is an industrial rotary laser used for precision leveling and slope measurement. Common failure modes include power‑supply voltage drop or intermittent startup, front‑panel LED/indicator failure, optical misalignment of the rotating head, and firmware corruption that can cause error codes such as “E01” (motor drive fault). First‑check diagnostics: verify 24 V DC input with a multimeter, inspect the laser head for dust or cracked optics, and review the on‑board diagnostic display for stored error codes. If power is stable but the beam does not rotate, test the stepper motor driver current and check for loose connector pins in the rotary drive module.[oss-gpt-20b]