My work began with the Beogram 4002’s arm lowering and tracking mechanisms, as is customary for me. My client had already addressed the cleaning and lubrication of the damper and solenoid linkages, so my task was to detach the linkage connecting the damper and tonearm. This required removing the sensor arm assembly, as shown here:

Extracting the sensor arm involved removing two screws at its base:

The linkage could then be detached:

After cleaning and lubricating the bearing, I reassembled the arm and secured it back onto the carriage. I then aligned the arms perpendicular to the carriage tracks and ensured they were parallel to one another:

With this complete, I replaced the incandescent bulb originally used for the tracking sensors with my LED-based tracking sensor light source. The image showcases a comparison between the old and new light sources. The placement of the LED precisely matches the filament location on the original bulb:

A blue trimmer located on the back of the LED unit allows for light intensity adjustments, simplifying the tracking sensor sensitivity tuning process:

This image displays the original light source in its designated position:

And here’s the newly installed replacement:

The carriage restoration concluded with cleaning the threaded rod responsible for carriage movement and replacing the pulley. This picture reveals the original plastic pulley, which was cracked and had been reattached with glue (an alarming sight!):

Once the fragmented pieces were removed from the rod, I installed the newly crafted precision aluminum pulley:

A truly impressive improvement! For those interested in upgrading their 400x with a similar pulley, please send me an email or use the contact form on the right. I’m happy to connect you with the “Pulley Master”! As a reminder, all parts showcased on this blog are available to fellow enthusiasts. Now, onward to restoring the electronics!