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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...

Showing posts with label rust. Show all posts
Showing posts with label rust. Show all posts

Saturday, May 12, 2018

Beogram 4002: From Oil Cleanup to First Operational Test

My restoration plan for this Beogram 4002 project encountered a detour. After restoring the main board I intended to do the reservoir capacitor replacement and the output board. However, the rust and corrosion I found when starting the project got me thinking that I need to address that first. Applying rust neutralizer and painting takes time because you have to let the parts dry between applications.

Here are a couple of pictures of the worst rust spots again.























This Beogram is interesting in that it has some really nasty looking rust damage but the overall condition of the turntable is actually really good.

I decided to apply three coats of the rust neutralizer.























After 24 hours I painted the parts with black, oil based paint.





























Now I can proceed with the normal restoration. Since I had to disassembly the chassis to get to all of the rusty areas I discovered there were a few puddles of oil in the Beogram. People often make the mistake of applying thin oil to the Beogram turntables...and too much of it.




























Thin oil applied to the moving turntable parts end up being slung against other turntable parts. My next step was an oil clean up job.

I had removed the floating chassis to get to the first oil spill.

The tangential arm assembly needs going over anyway so I moved those steps up in my project schedule.

There is a lot of wet oil around the spindle bearing nut. That means thin oil instead of grease was used on the tangential arm drive spindle.























The tangential arm drive spins as it moves the tonearm and you can imagine how that would really throw loose oil like this around.

There was quite a bit of oil on the surface of the floating chassis but I found the most gathering of oil in the tangential drive sensor housing.






















The oil could interfere with the sensor preventing it from working properly.
I cleaned all of this area up and put the tangential drive sensor assembly back together.
























The tangential arm sensor should be in good shape now when I get to the record tracking adjustment procedure.

I moved on to the arm lowering damper. It was in good shape but I cleaned it and applied some light grease to its piston.






















I discovered the tangential drive pulley had small, hairline cracks as most do by now. That makes the pulley deform when the set screw tightens to the spindle shaft. The result is a wobbly running spindle.






















I am still amazed that the transport bushings on this Beogram are still really good. That is a rare sight.
Here is the new pulley. It is one of Nick's aluminum pulleys and it works as great as it looks.
























I also performed and initial tonearm tracking force calibration. It is easy to work on the tonearm assembly when it is removed like this.
























Note that I installed the usual Beolover mod where a small locking nut is added to insure the tonearm counter weight stays where the calibration put it.

That takes care of the initial tangential arm mechanical restoration tasks. Now I can get back to the electrical step of replacing the reservoir capacitor.  Here is the original one as pictured before I started the rust and oil clean up.






















Here is one of my favorite Beolover replacement parts. The 3D printed housing with the new reservoir capacitors.
























Before this nice assembly I use to glue the new reservoir capacitors to the cabinet floor. This is so much nicer and it uses the original Beomaster clamp.

I am getting close to running an operational test on this Beomaster. First I went ahead and changed the capacitor and muting relay on the output board. I still need to add the grounding switch but I will come back to that.

Here is the before picture of the output board.





















...and here is the after.































Now for some reassembly. I have to re-install the rust repaired chassis components so the floating chassis can be put back. I also have to re-install the DC platter motor that Beolover restored for me.

Here are some pictures of various components as they are fitted back into the Beogram chassis.




















































































Whew. It is looking like a Beogram again. I should be able to install the sub-platter, belt and top platter then give this Beogram a test run.












































I love it when things work the first time.

Even though this Beogram thinks it is ready I don't trust it enough to try a record yet. I will run through the service manual checks first to make sure it is ready to play a record.


Tuesday, May 8, 2018

Beogram 4002: New Project From Houston

I get to switch gears from Beomaster restorations back to a Beogram project next. I love working on both so either way it is a treat for me. A gentleman from Houston brought me a couple of Beogram 4002 Type 5513 turntables he had acquired some years ago. Eventually they began to age and stop functioning correctly.  Like most Beogram 4002 owners he found that he missed playing vinyl records on them so he had to get them restored.  I am lucky enough to receive the task and look forward to getting these back 100% working again.

One at a time though.

These were functioning well for the owner not too long ago so the Beograms are in decent shape. Here is the first Beogram turntable opened up.






















I already removed the DC platter motors back in March and sent them to Beolover for a full restoration. I have those motors back and they have been waiting for the rest of the Beogram restoration to catch up.

There are a few areas inside this Beogram where rust is starting to look bad. I will clean those up and put a stop to the rust. 

The Beogram phono DIN plug is badly corroded as well and the best solution there is to replace it.






















Here are a couple of pictures of some of the chassis components that have rust.























Interestingly this Beogram 4002 is one of the rare few I have seen where the plastic transport bushings around the floating suspension locking screw are still intact. They are still soft and in good shape. Most of the units I see have brittle bushings that have cracked and are in a million little pieces scattered throughout the Beogram. I will treat the bushings with some plastic restoration fluid that will keep them from drying out.






















The main circuit board looks in great shape. No signs of heat stress or corrosion there.






















The tangential arm assembly also looks to be in good condition. 






















Recapping the main board, replacing relays and speed trimmers along with cleaning and adjusting the tonearm mechanics should get this turntable back to working the way it was designed. The restored platter motor along with the replacement of the trimmers and speed indicator lamps (with Beolover's LED replacement modules) will have this Beogram spinning vinyl better than ever.

Time to get to work.

Sunday, September 13, 2015

Beogram 4000: Installation of a Neutrik Gold Plated DIN5 Plug

Another standard upgrade that I do for Beogram 4000s is installing a new gold plated DIN5 plug. The original ones are not gold plated and tend to be a bit rusty after all these years. This Beogram 4000 was not different:

This shows it taken apart in contrast with the new shiny Neutrik plug (Newark 27B4483) insert:

After cutting the old plug off, I prepared the cable for the new plug. This is a good length for taking the outer insulation off:


It is a good idea to strengthen the signal leads a bit with solder after taking the insulation off. This makes it much easier to solder them nicely into the tabs of the pins. then it was time to solder the plug on:

And here the lovely sheen of new gold contacts:

This is golden beolove!