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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, April 26, 2021

Beogram 4002 DC Motor Restoration

I recently received a Beogram 4002 DC platter motor from Norway for some TLC. This shows the motor as received:

I took it apart to extract the bearings for oil infusion:
The bearings are the two small donuts on the black pad up front. I immersed them in motor oil and pulled a vacuum. Immediately, bubbling started as the air was drawn from the porous bearing material to make room for fresh oil:
After about three days the bubbling stopped and I extracted the bearings:
Then I reassembled the motor and installed it in one of my Beogram 4002s for a 24 hrs RPM stability test with the BeoloverRPM device:
It logs the RPM in 10s intervals for extended periods of time. This is the curve I measured for this motor.
This is as good as it gets with the Beogram 4002 DC platter motors! This motor is back in business and will be sent back to Norway soon!


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