This Beogram 4002 turntable had a damaged part (the tracking sensor aperture) that was bent and obstructing the arm’s movement. This issue prevented the tracking system from working correctly. The initial setup used an incandescent light bulb:

Upon removing the bulb housing, it was evident that the aperture was bent and rubbing against the optical sensor housing:

The aperture was carefully straightened, and the bulb assembly was replaced with a new SMD LED light source. This upgrade included a potentiometer for adjusting light intensity, improving the tracking sensor’s sensitivity. Here’s a comparison of the original bulb and the SMD LED replacement:

The new assembly was a direct replacement, requiring no modifications:

After installation, the tracking sensor sensitivity needed calibration. To avoid potential damage, a less valuable record and a worn cartridge were used during this process. Here’s a glimpse of the coarse adjustment of the tracking sensor assembly:

A detailed video demonstrating the tracking sensor adjustment process is available for those interested in attempting this repair. The video uses a prototype assembly, but the procedure remains identical.