Featured Post

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, January 23, 2023

Beogram 8002 Type 5633: Floating Chassis Restoration Tasks

I wrapped up the work on the Beogram 8002 floating chassis. It should be ready for some functional testing of the turntable operations in the next blog post.

Here is the floating chassis before starting the restoration work on it.

It has a bit of dust as you would expect but nothing major to clean up or repair.

I removed the center hub to inspect the tachodisc and speed sensor.

Next is the disassembly of the tangential arm assembly for inspection, cleaning and lubricating.
I will also check the arm raise/lower solenoid and mechanical parts. 

The arm lower/raise mechanics looked good.
While the arm assembly was turned over I took the opportunity to align the tonearm height with the sensor arm.

Interestingly this Beogram 8002 unit has a little, square rest plate for the tonearm height adjustment screw.  Usually there isn't anything there to keep the screw from contacting the metal back of the tonearm.  That can cause problems with the arm lowering operation so I often have to place a small piece of Dura-Lar plastic there.  In this case, the problem is already taken care of.

Now it is time to clean the old oil and grease from the spindle, rails and attachment pieces.
Then re-lubricate everything and reassembly the arm assembly.

Because this Beogram 8002 was configured for the North America market the rear guide rail has rubber tip ends to dampen any vibrations from the 60 Hz line voltage.

I applied some rubber restoring fluid to the rubber ends when I reassembled the arm assembly.
For re-lubrication of the spindle I still use the original B&O combination of Rocol MTS 1000/2000  with Mobil NUTO H32 mixture. However, a good modern, synthetic oil will also work fine.  Just don't over lubricate the spindle where oil flies off when the spindle spins.  
On the shiny guide rails I apply either some M-kote DX Paste Grease or some Tri Flow Dry Lube.
At the pivot points of the spindle where it attaches to the chassis I use a little bit of Tri Flow Red Grease.

Here is the tangential arm assembly put back together with the tonearm aligned with the sensor arm.

There were a couple of electrical restoration tasks left to do that I didn't complete on the previous post.

One is the replacement of the phono muting relay.
I replaced the original muting relay with one I sourced from Beoparts.

I also installed my usual test connector for adjusting the LDR sensors that are used for the forward and reverse arm scanning operation.  It is kind of a pain to connect DMM probes to make the voltage measurement while adjusting the sensor aperture so I install a three wire test connector that allows checking (and adjusting) the LDRs without opening the Beogram 8002 into its service position.

The Beogram 8002 turntable components can now be assembled and tested.

No comments:

Post a Comment

Comments and suggestions are welcome!