Beomaster 8000 Terminal: Replacement of Corroded Battery Terminals and the Design of a New 3D Printed Battery Cover

The Beomaster 6000 that I just repaired came with a non-working Beomaster 8000 Terminal remote control. It turned out that a simple replacement of the corroded battery terminals was enough to restore power and with that the functionality of the unit. However, this Terminal was also lacking the battery cover and the rubber bumpers that keep it from sliding off polished furniture surfaces. Since this is not the first Terminal that I saw with lacking battery compartment cover, I decided to design a 3D printed replacement part. Here are a few impressions of my progress:

This shows the original corroded battery terminals:

and the installed replacement:

After a few design iterations I had a fitting battery compartment cover:

This shows it in comparison with the cover I extracted from one of my Terminals. Here the outside surface of the part:

The part has rubber bumpers like the original. Thir location is slightly different due to stability considerations, but they do their job very well.

This shows the part installed:

Pretty, eh?? The latch works exactly like in the original part. The cover can be extracted from the ouside by inserting a small flat blade screw driver and then lifting it out.

But why in orange you may wonder?!? I usually use orange for prototyping since I have an ample supply on hand these days for filling CleanerVinyl orders. Orange also reveals more details than black in photographs. But of course the final version was printed in black. Here in comparison with the original:

And in more detail:

If you are lacking the battery compartment cover on your Terminal, this part is available for purchase. Just send me message (use the contact form on the left).

The remaining task was to replace the worn/missing rubber bumpers at the lower end of the Terminal body. This shows a newly installed bumper (right) in comparison with a broken off original bumper (left):

And both replaced:

The final step was to clean the unit. I employed my ultrasonic cleaner (another benefit of the CleanerVinyl project...;-) and the buttons and housing came out in a fairly pristine condition:

What a lovely classic design! This is Beolove!

Beomaster 4400 (2419): Headphones Jack Restoration

I thought I was done with the Beomaster 4400, but I had completely forgotten about the jammed in 3.5 mm headphones adapter:

After removing it it looked like this:

While I was blissfully listening to some nice jazz on the public radio on this lovely Beomaster 4400, it occurred to me that there was something missing. Then it dawned on me that the receiver was lacking its headphones jack bezel. It must have been pushed in when the adapter hit something hard and then went missing after someone opened the Beomaster up to have a look. The headphones jack was also mashed in. Ruffians!:

After taking the jack out it looked like this:

I straightened the jack bracket as good as I could with my vise. In the meantime I obtained a spare bezel. This allowed me to finish up the repair:

With a straightened bracket the jack sits close enough to the bezel to hold it in place from the backside. From the front it looks like this:

Too bad that the banged-in adapter damaged the panel cutout a bit, but I guess for a more than 30 years old unit, this Beomaster is in pretty nice shape nonetheless.

Allright...looks I am finally done! All good in Beomaster land! I really started to like listening to this receiver, but now it is time to ship it back!

Beomaster 4400 (2419): Missing Preset Cover Replacement

It seems the Beomaster 4400 (2419) that I recently restored runs stable. I have it connected to my Beogram 4002 and I also tested it with the Beocord 9000 that I am working on right now, and everything functions very nicely. The final task was to replace the missing preset cover. There must be a big heap of these lost covers somewhere on this planet, but as long as we do not know where this Preset Cover Shangri-La is, getting authentic reproductions (injection moulded as the originals) from 'Dillen' (beoworld.org) is a great option. He recently sent me a few, and I installed one. Fits very well, maybe a bit tough to remove, but that will keep it (hopefully) away from their hiding place...;-). Here is a pretty shot of the cover:

Time to double box this Beomaster 4400 and send it back to its owner. That is the hard part of Beolove! Constant separation trauma...love can be pain...;-)

Beomaster 8000: Repair of a Broken Out Control Panel Lid Spring

The last Beomaster 8000 that I renovated came back to my bench after suffering shipping damage on the way home to its owner. There were some broken traces on the uProcessor board and a broken out button PCB in the control panel). After I fixed these issues and put it back together, I set out to write a proud email to the owner announcing the swift return of this Beomaster, this time double boxed. A few seconds after I hit the 'send' button, a loud crack happened and a piece of plastic ricocheted past my head. This is what I found. One of these pieces was located on the other side of my work shop:

First I did not quite understand what happened, but then I realized this part must have originated from the Beomaster that sat on the bench next to me! I looked around and found this situation on the back of the control panel lid:

The spring that opens the control panel had broken out of its plastic retainer and the lid hung limp on its hinges. No more springy opening after pressing the bar. This spring is surprisingly strong, and while the lid is closed it stores the energy needed to open the panel. This energy released creating a projectile.

First I asked around if anyone had a decent condition lid (3D printing still has 'finish issues; it is difficult to produce good lucking parts for exterior repairs), but I came up empty. So I further examined the situation and came up with a low impact strategy to fix it. Dillen of Beoworld.org advised me that the plastic bar that holds the spring mechanism can be slid out to the side of the lid. I opened the Beomaster up again and extracted the lid. Then, indeed, the part easily came out from its groove revealing that it is hollow. This opened up a route to a 3D printed fix. Here is a picture of the part that I had printed on a Stratasys uPrint printer in ABS:

I only had access to white filament, so I had to paint the part black on the visible areas. This part fits precisely into the gap in the plastic part and over the spring:

Fully inserted:

Then it was time to test the part under stress. I slid the bar back into the lid:

Then I put everything back together. Here is a view of the Beomaster from the back:

Not too bad...hardly visible, and if one does not know how it is supposed to look, one could almost think this is how it was designed. The Beomaster went back into my Beosystem 8000 to play with its old friends the Beogram 8000 and the Beocord 9000. I want to give it a few days of testing to make sure the shipping damage has been remedied in a stable way before I ship it out (this time double boxed...this experience demonstrated that an original B&O box is just not enough protection for today's shipping environment.

Bang & Olufsen MMC Cartridge Protector: Dimensionally True Reproduction with Stereolithography

I finally wanted to try the clear resin (or 'maker juice' as it is called in the Makerworld...;-) on the Formlabs Form 1 printer. So I sat there one recent night and designed a faithful reproduction of a MMC cartridge protector. Seems whenever one comes across a cartridge the protector is lost. I have several MMC cartridges around the house, but only one protector. Now it seems this problem has been solved. Here are a few pics of the finished part. I guess, "transparent" is a matter of definition, and the 3D printed 'clear' material still seems to have a bit of a problem with it. But on the other hand, the outcome really was not too bad. Definitely usable, and definitely much better than a broken off cantilever! Here we go:

 The small details like the two protrusions that clamp the protector to the cartridge (below the "UP" lettering) are quite correct in their dimensions and the cartridge clamps in nicely, however with bit less 'grip' than into the original protector. This is a result of the softer material quality of the printed plastic. I could probably increase the wall thickness a bit (or just be happy with the way it is!..;-):

Beocord 5000 (4715/4716): Polishing of Plexiglass Panel

I started working on another Beocord 5000 (4715/4716) restoration. It appears that cassette tapes are making their comeback to catch up with vinyl...;-). What better way to spend a Saturday afternoon than with making a mixtape for a loved one! I miss this way of showing affection...these days, all we do is swap Spotify playlists...not much Labor of Love in that! 

In this spirit I started out with polishing the badly scratched panel of a spare Beocord 5000 as a practice run for the better-condition panel that will go with the Beocord once I am done with its internal restoration. I felt I needed a practice run, since I worried about the coating layer that is on the plexiglass panels of these B&O units. It appears they felt that this coating would improve the shininess of the surface, since it appears that it does not change the tint of the panel. After I polished it, the tint appeared very similar despite the missing coating.

Here is a picture of the heavy damage of this panel:

I essentially followed the polishing procedure that I applied to the panels of my Beolab 4500 speakers. See here and here for a detailed description of this process.

The main difference with the Beocord 5000 panel occurred during the first sanding step with 220 grit dry paper to get rid of the heavy scratches. When I started sanding, immediately the coating disintegrated into tiny shreds and I observed this wool-like appearance:

After I worked through this step everything was as usual and I progressed through the ever finer sandpapers of the Micromesh polishing kit. A pretty good workout! After I went through all the sanding steps I followed up with their polishing solution, and then I ended up with a pretty nice result:

There are still a few minor scratches that are visible to detailed scrutiny, but I think this panel would now look very nice in the usual setting in a living room etc...It is very difficult to get them absolutely perfect since the slightest oversight in one of the polishing steps requires to go back to this step and repeat the entire procedure from that point on.