Restoring the keypad and chassis on a Beogram 4002

After replacing the light bulbs on the Beogram 4002, I restored the keypad. The original varnish and black paint were worn down from years of use, and several buttons were unresponsive due to oxidised contacts.

The keypad was carefully separated from the chassis using a spatula. I stripped the old glue and varnish using NitroMors in a ventilated area. To ensure a durable and clean finish, I consulted a local auto paint expert and switched to 2K varnish applied with a spray gun and compressor. The results were excellent—smooth, clean, and very close to the original look.

The black-painted chassis sections were masked, cleaned with isopropyl alcohol, and repainted using a primer and durable black topcoat.

Next, I cleaned the electrical contacts. The contact springs and bridges were removed and cleaned with ketchup, which effectively removed oxidation. Other components were cleaned with isopropyl alcohol.

For reassembly, I used a 2K epoxy recommended by another hobbyist. It provided enough working time for alignment and cured strong. I used clamps and a custom 3D-printed bracket with a felt pad to hold the keypad in place without damaging the fresh varnish.

Once cured, I glued the final plastic parts in place, reinstalled the PCB, and tested all buttons—everything worked as it should.

Now all that remains is final calibration and testing, which I’ll do using a custom-built tachometer. More on that soon.

If you're working on a similar restoration, please don't hesitate to reach out.