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Beolover SyncDrive: DC Platter Motor Replacement for Beogram 4002 and 4004 (Type 551x and 552x)

Late Beogram 4002 and the 4004 (Types 551x and 552x), which have DC platter motors instead of the earlier synchronous AC motors usually suff...

Tuesday, March 8, 2016

Beogram 4000: Replacing the Light Bulbs in the Control Panel and Gold Plating of the Keypad Contact Terminals

The next step in my current Beogram 4000 restoration process was to rebuild the control panel. I usually replace the incandescent light bulbs with LEDs and clean the key pad contacts. In this unit three of the four bulbs were broken, confirming that it is a good idea to switch to LEDs. LEDs have a much better reliability than incandescent bulbs.
This shows the original bulbs:
I recently had the SMD LED boards that I designed to replace the position scale illumination bulbs (the two on top) professionally manufactured. Here is an impression of the redesign:
This shows the boards installed. I also replaced the two bulbs that illuminate the red RPM trimmer shafts from below with red LEDs:
After replacing the bulbs I turned my attention to the contact terminals of the switches that are actuated by the keypad. They were highly oxidized:
Inspired by some pictures a customer sent me recently where he had his contacts Ni plated I decided to gold-plate these contacts. I extracted the terminals, cleaned them with a fiberglass pen, and then I electroplated them. Here is an impression of the as-original terminals after extraction:
and after gold plating:
After the plating process I reinstalled them:
Very pretty! This is Beolove!

I noticed that one of the two brackets that hold the strobe mirror in place was missing. So I printed myself a replacement:
and epoxied it in place:
Loosing this mirror would be a difficult item to fix, so it is better if that is prevented right from the start!

After this I had a look at the switches that are triggered by the carriage. They usually are also oxidized, but in this case I found a pristine situation. Maybe this board was replaced at some point. It looks almost new!:
I left them as they were and just gave them a light Deoxit D100 coating to reduce potential oxidation down the road.

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