Following the control cluster restoration of a Beogram 4000, attention turned to the PCBs. The main PCB was initially in average condition.

The standard procedure involves replacing all electrolytic capacitors with high-quality Japanese equivalents, installing a new RPM relay, and substituting the original single-turn RPM adjustment trimmers with 25-turn encapsulated ones for increased precision. Capacitor replacement is critical as aging and potential leakage can lead to operational issues. The RPM section, shown below, exemplifies this.

The components were subsequently replaced, resulting in a refurbished RPM section.

Access to the RPM trimmer adjustment screws is maintained through the original trimmer holes, enabling on-the-fly RPM adjustments during operation.

The main PCB, now restored with all new components, is ready to be reinstalled.

The power supply PCB, unlike the main PCB, only requires attention to two electrolytic capacitors (indicated by red dots).

Accessing the solder points necessitates lifting the PCB, often requiring the desoldering of the primary winding leads. These leads include an inline fuse housed within a protective yellow plastic tube, visible at the back of the PCB. During the desoldering process, one of the fuse mounts detached.

The fuse was discovered to have broken, with the metal ends separating from the glass tube.

After replacing the capacitors, a new fuse was fitted into the mounting cups, which were slightly bent to ensure a secure connection.

The fuse was then soldered back into the primary line and protected with a heat shrink tube.

Finally, the board was secured back in place.

The next steps will involve addressing the reservoir and motor capacitors, as well as the AC platter motor.