During my current restoration of a Beogram 4002 (5523), I replaced the incandescent bulbs that light up the RPM trimmer adjustment scales. I swapped them with custom-designed SMD LED assemblies for longer-lasting illumination, which is beneficial for those aiming to use their Beogram long-term. Here’s a look at the latest iteration of the LED boards before installation:

Fellow enthusiasts can acquire these assemblies. This video demonstrates the LED board installation process, starting with removing the trimmer panel and its existing light bulbs:

The LED PCBs are then positioned within the panel:

The boards are designed to fit seamlessly under the original covers:

Finally, the panel can be reinstalled. The subsequent images showcase the LED boards in operation. The red scale hands appear red due to the red/green bi-color LEDs used in the replacement. These LEDs are calibrated to mimic the look of incandescent lighting while emitting red photons that reflect off the red scale hands.

Using single-color amber LEDs wouldn’t achieve this effect. The hands would appear grayish and only turn red when exposed to external red-containing light sources, such as incandescent room lighting.