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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...

Monday, May 2, 2022

Beogram 4000/2/4: Update of Sensor Arm LED Assembly. No More Crumbly Flex-PCB Mess!

I recently re-designed the sensor arm LED assembly for Beogram 4000, 4002, and 4004. The previous version using a flex-PCB proved too difficult to install for some customers. My updated design is based on a small 'hard' PCB that fits precisely into the bulb compartment and uses an insert for proper positioning (it is important that the LED is approximately in the spot the lightbulb filament occupied).

This shows the new components:

And here a still from the video below that shows the LED 'in action':

The LED board produces a nice focused spot on the platter and also the B&O logo is lit up properly in the correct hue.
I updated my original sensor arm video and it shows now how to install these parts in Beogram 4002 and 4004. The video also shows how to update the record detection circuit. It usually benefits from installing a new transistor for amplifying the sensor signal. The procedure for Beogram 4000 is similar, but naturally the board looks a bit different, i.e. you will need to find the transistor for the sensor signal amplification via the service manual. Enjoy!:

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