Beogram 4004 Type 5526 - Restoration Project - Initial Assessment and Cleaning

2026 seems to be the year of the Beogram 4004 turntable...restorations that is.

This post begins another nice Beogram 4004 restoration project.  

Here is my assessment.

The Beogram is in nice shape and very clean.

The Beo4 remote control pictured next to it is because this Beogram 4004 will be getting a Remote Commander that is paired to the Beo4 controller.

The middle, top of the dust cover has a rather noticeable scratch.  I will try to buff it out so it isn't so prominent later.  This Beogram might end up getting a new dust cover from dksoundparts.

The keypad looks nice as well as the other turntable deck components.

The inside of this Beogram 4004 also looks to be in really great condition.
Of course there is the usual floating debris of disintegrating transport lock plastic material.

Everything else looks great though.

The tangential arm assembly looks good.

I removed all of the transport lock assemblies so I can take out the floating chassis components to work on them.

The main circuit board and the output/remote control board look good...ready for restoration.

Here is the cleaned up cabinet and the removed nuts and bolts.

...and here is the removed floating chassis assembly.  I will start the restoration work with that set of components first.

I did not include any pictures of the DC platter motor for this Beogram.  That is because this Beogram 4004 will be getting a Beolover Sync Drive platter motor.  

In the next post I will start disassembling, cleaning and lubricating the floating chassis components.

Beogram 4004 Type 5526 - California Project - Initial Assessment and Cleaning

Here is an initial assessment and cleanup of a nice Beogram 4004 Type 5526 turntable sent to me from California.

 

The platter was packed separately so it isn't in the photos.

The keypad and wood trim look great.

You can see that the tonearm has a problem.  Fortunately it doesn't appear serious.  It is just missing one of two M2 screws that attach the arm to the base.  I have spares for that.

The dust cover is in decent shape although the aluminum trim piece has a buckle.
The owner sent me a new dust cover to replace this original one however so this Beogram will have the new one installed when I am finished.

The inside looked good at first glance.

When I removed the circuit boards and floating chassis I discovered some sort of spillage had occurred in this Beogram's past.  Some sort of liquid was spilled?

Amazingly, this Beogram has original transport bushings that are not dried out and crumbling apart.
They are intact and still soft.  I will leave them in place and coat them with a rubber treatment to make sure they stay soft.

Also note in this photo that I installed the missing M2 screw on the tonearm.  It still needs adjusting of course but that will come later.  For now the arm isn't dangling around anymore.

As I removed components from the floating suspension frame I looked for more remains of whatever was spilled into the Beogram.

Besides a dry film on the Beogram part surfaces, there were a few places where there is corrosion.

The suspension wire assembly at the back (where the spillage must have occurred) has corrosion so I will replace that part in the restoration process.

Not surprising the pivot posts for the tonearm operation were gummed up from the liquid that spilled.
The lever that lower and raise the arm would barely move.

I didn't want to wait until later to start cleaning this residue up so I decided to clean as I went through the initial assessment.

The cleaning up wasn't too bad.  I only had to apply corrosion cleaner to a few places.  Most of the residue scrubbed clean.

The arm lowering and raising assembly is back working smoothly again.

The pulley belt for the tangential arm is all stiff, dried and broken. That isn't unusual but is kind of surprising seeing how the transport lock bushings remained soft over the years.

Really amazing is the condition of the phono DIN plug.  It is corrosion free.

The old tangential arm drive pulley is going to be replaced with a new, aluminum pulley so I removed it and cleaned up the tangential arm drive spindle.  I also cleaned the guide rails, spindle nut and cover.

This Beogram 4004 is now at a point where I can begin working on the restoration of the mechanical parts for the turntable.

Michigan Beogram 8002 Restoration: Final Reassembly

I left off in the previous post of this project with a broken Beogram 8002 cabinet hinge guide...for the service position hinge.

That type of break on these cabinets is difficult to repair with any reliability.

I have tried unsuccessfully to repair these before and it was the same section of the cabinet hinge that is broken on this Beogram 8002.

Without a good spare Beogram 8002 cabinet to replace this with, I had to attempt a hinge guide repair again.

This broken hinge guide presented a new challenge because it also had a crack in it.

So I had two repair steps.

One was to reinforce the broken piece that I needed to glue back onto the cabinet frame.

The second then, was to glue the reinforced piece onto the cabinet so it is strong enough to support any pressure from the metal hinge rod.

I used two glue types for this repair - Bondo Steel Reinforced epoxy and JB Weld reinforced epoxy.  The latter was used in the last fill of the broken section.

The repair effort turned out successful but the various glue steps and time waiting for epoxy to cure took a total of three days.

Here is a look at the repair scar after I was done.

It still isn't pretty but the scar is smooth and is not visible unless the Beogram is upside down.

The important thing is that exercising the cabinet open to the service position and back closed does not cause the repair to break again.

Since the service position is not something a Beogram 8002 owner will typically use, I am satisfied with the repair.

It means the internal Beogram 8002 components can be reinstalled.

Another quick cabinet problem I decided to address was the metal lid hinge damping.
The Nyogel 767A damping grease I used in the previous post did not result in a slow enough closing of the lid.  I could hear the lid when it reached the closed position.  With proper damping the lid should be silent.

I pulled the metal hinge bar out again from the section holding the metal lid to the cabinet so I could remove the lid for re-greasing.

The area highlighted in yellow is where I re-applied damping grease.

This time I used Nye Lubricants PG-44A Grease.  It is much thicker than the Nyogel 767A damping grease and the result was just what I was looking for.

Next was the re-installation of the internal Beogram 8002 components.

That meant removing my test point leads from PCB 1 and attaching the metal lid to the microcomputer assembly (PCB 2).

I put some thermal conductive tape on the uC IC.

Applied some thermal grease.

Attached the metal lid and checked that the heatsink on the lid was pressed onto the thermal grease.

Next up should be some photos of the reinstalling of the floating chassis assembly, PCB 1 and 2, the transformer assembly and the Control Panel assembly.

However, I was so concerned with the service position hinge repair that I spent all of my effort carefully installing the components and did not take any photos :-(

So instead, the next photos are after the internal components were installed.

Here is a sequence of photos I took as the metal deck lid was closing.  It shows the slow lowering of the lid that now touches down onto the cabinet silently.

I did a little polishing of the dust cover and I will now move on to some record listening to wrap this project up.

The only issues with this Beogram 8002 are a couple of cosmetic problems.
The left side front of the cabinet has some small pieces of rosewood veneer missing and the Beogram platter is not pretty. 

Again, the Beogram 8002 platter should never be cleaned with anything other than some very mild soap (if even that) and distilled water.  A pristine Beogram 8002 platter should only be dusted with a dry cloth.  Platters like the one in this project were exposed to some sort of cleaning fluid at some point and the top coating from the B&O factory has been damaged.

That doesn't affect playing records great which is what these turntables do.

Beomaster 5500 Type 2333: PCB Restoration Tasks

In the previous post I assessed the restoration tasks of this Beomaster 5500.

This post shows the work performed on the Beomaster 5500 circuit boards.

The first step was to remove the boards that will need to be worked on.
Here is a photo of the Beomaster 5500 prior to removing the boards.  The boards that will be worked on are labeled in the photo.

The following pictures are a sequence of Beomaster 5500 photos showing the boards being removed.

The last photo above shows the Microcomputer board removed...so I will start with that one.
Here are the before and after pictures of the Microcomputer board restoration.
There are just two electrolytic capacitors in this board.
There is also a CR2430, 3V Lithium battery.  It still measured 3V but it is still good to go ahead and replace the battery with a brand new one.

Note that for installing the new CR2430 battery I installed a battery holder for it.

The next board assembly is the Cooling Fan assembly.  It also has two electrolytic capacitors that I replaced.

The FM board came next.

Here is the FM board as it was received.

Here is the FM board after the electrolytic capacitors were replaced.

Here is the recapped Preamplifier board.  I didn't take a stand-alone before recapping photo of it so here are a couple of after recapping photos.  I replaced all of the signal path electrolytic capacitors with non-polarized, Nichicon audio capacitors.

Note that the highlighted Muting Relay had already been replaced so I didn't change that component.

The last Beomaster 5500 circuit board I worked on is the Power Supply and Output Amplifier board.
Here it is removed from the cabinet prior to any restoration work.

The white thermal compound on the heatsink assembly is just getting to the point where it feels a little bit dry.  For that reason I decided to remove the heatsink, clean the old thermal paste off and put new thermal protection on during re-assembly.

Here are photos of the heatsink removal and thermal paste cleanup.

Here is the Power Supply and Output Amplifier after I replaced the electrolytic capacitors, power supply relay and trimmer resistors for the output transistor bias.
There are two signal path blocking capacitors (2.2uF) for the audio signal from the Preamplifier board to this board.  I replaced those two capacitors with the same type I used in the signal path on the Preamplifier board.

Here is a closer photo of the new trimmer resistors.

The original power supply relay looked like this, de-soldered from the board.

The relay (RL1) still works but judging by the heat marks on the board and the fact that the Muting Relay (same type of relay) was already replaced...it is a good idea to go ahead and replace this relay.

I used a modern, enclosed relay.  It has two extra relay contacts that I had to cut off so that I end up with an identical mounting foot print.  I have used this replacement relay before on my own Beomaster 5500 and Beomaster 5000 amplifiers so I know it works well.

The next steps are to re-install the output amplifier board heatsink assembly then re-install the boards back into the Beomaster 5500 cabinet.