The initial step for restoring a Beogram 4002 turntable typically involves reconditioning the arm lowering mechanism and calibrating the tracking system. In this instance, hardened lubricants had affected the mechanical operation, and excessive sensitivity in the tracking sensor led to uncontrolled carriage movement after the arm lowered. The solenoid and damper assembly is depicted below:

The restoration began by disassembling the mechanism, cleaning all parts, and applying fresh lubrication:

A video illustrating the tracking sensor adjustment process is available. Following reassembly, the sensor arm was removed to access the damper-to-arm linkage:

Another video demonstrates how to reach and lubricate the damper-to-arm linkage. Reassembly allowed the tonearm to align with the sensor arm, guided by a notch on the counterweight assembly’s backplate:

When correctly executed, both arms should be perfectly parallel and form a right angle with the enclosure’s back:

Next, the tracking system required attention. Installing an LED-based light source is advisable for enhanced long-term consistency. The original tracking sensor’s light source is shown here:

The newly designed SMD LED replacement unit is pictured below:

The original incandescent unit is included for visual comparison. This assembly, like all components used, is obtainable by fellow enthusiasts.

After installing the new light source, the tracking system’s feedback loop sensitivity was adjusted. This involved an initial coarse mechanical adjustment using the eccentric mechanism behind the light source, followed by fine-tuning with the blue trimmer potentiometer built into the LED unit:

A video demonstrating the tracking sensor adjustment process is available. For this adjustment, it is recommended to use an expendable LP (a free jazz record by Sam Rivers is a fitting option) and avoid using a high-quality cartridge. Without careful adjustment, the carriage could potentially drag the stylus across the record surface. After these procedures, the tonearm and carriage functionality was restored. The next phase involves reconditioning the electronics.