BeoGram CD X: Restoring the door motor

In the previous post about this BeoGram CD X unit I got it working again by reworking the board vias. While the CD X was playing CDs again its motorized door was struggling with opening and closing.

I ordered a new belt for the door motor and received it from Martin Olsen this week.

This post shows the opening back up of the CD X and changing out the belt motor plus checking capacitor 2801 (220uF, 10V) of the door's motor drive circuit. The capacitor is sometimes faulty.
I will also show the restored vias on the Servo board (PCB 04) as I promised in the first CD X post.
Here is the CD X with the bottom cover removed. You can see the door motor assembly on the left.

I removed the top cover from the main CD assembly to make easier work of the belt replacement.

While the CD assembly is out I will take this time to show photos of the Servo board (PCB 04) I restored the vias on earlier.

Continuing with the CD X motor belt and capacitor 2801 replacement, this next picture shows the CD X top cover with the door motor assembly.

The door motor belt cannot be replaced without some more disassembly so the next few pictures illustrate taking the motor assembly apart to get at the belt.

To remove the gear blocking the extraction of the belt there is one of those pesky C-clips. Pesky because they are very easy to lose.

I had to loosen the two screws on one door switch assemblies to give enough clearance to remove the large, white, plastic gear. Finally the belt as accessible.

I installed the new belt and reassembled the motor assembly.

Now it is time for the 2801 capacitor.  I de-soldered and removed it. Sure enough the 220uF capacitor only measures 65uF.

Replacing it I can continue the reassembly of the CD X.

A test of the restored door motor assembly now shows the door opening and closing with ease.
This CD X is ready to go back into service.

Beomaster 8000: Tackling the Lid Damper

On these last two Beomaster 8000 and Beocord 9000 projects the owner had to have the damper devices for the lids removed as they had begun to leak fluid. This appears to be a common problem with the grease used by B&O on these series of components (Beomaster 8000, Beomaster 6000, Beocords 8000-9000).  Of course these these devices are thirty plus years old now so that has to be taken into account.

The Beocord 9000 I worked on doesn't have its damper anymore so I will replace it with a spare from another Beocord. The Beomaster 8000 damper is still intact although removed from the unit.

Here is a picture of the dampers I have available for this project and some of my future projects. The damper in the center has the most leakage of the bunch. Also shown are an original lid lever for the Beomaster 8000 and a 3D replacement lever that Beolover can provide. While the damper devices are the same between the various Beosystem components of this series, the levers are not. The Beomaster 6000 and Beocords require a different size lever. In the picture below the lever out of this Beomaster 8000 is not original. It is a pretty good hand-made replacement carved out of plastic. However, the plastic has become quite brittle and starts to break with the slightest pressure applied. The other lever is the Beolover 3D printed replacement. That is what I will use on this Beomaster.

This next picture shows a few of these dampers opened up. The two on the far right still functioned to some extent. The others no longer did much as their grease is pretty much gone. Two of the dampers had their plastic mounting clips melted in place as an attempt to keep the device sealed. I had to cut them open and they were pretty empty so the grease leaked out anyway. When I rebuild these my plan is to use black hot glue. I think it will hold secure enough yet allow disassembly in the future.

The next to last damper device on the right is the only one that had an additional, thin, white washer installed. I don't know if that is original or something that was added later by someone.

Here is a closer up picture of the dampers that still had functioning grease. Next to them is the replacement damping grease I will use. The thing to figure out next is how much grease is required for these dampers to operate correctly. Should the entire housing be filled? I hope not. One tube of this special damping grease is about $50 USD so it is quite an expensive product. However, it is made for the purpose of damping and claims it will not break down under high temperature.

Here is a cleaned out damper with the Nyogel applied. It is ready to be sealed up.

Beogram 8000: Re-Attaching the Aluminum Panels

Time for getting pretty! The Beogram 8000 that I am restoring right now is now running nicely. But, like in most of these units, the aluminum panels are detached. Usually, it is no big deal to glue them back on. Here are a few impressions:

The panels were originally attached with some foam based double sided tape. The foam degrades and the panels come off. This is what one typically finds:

A gooey sticky soft mess! Very difficult to remove. I usually put ethanol drenched paper towel wads on there (make sure the veneer is not touched) and then wait for 30 mins:

After that the goo has softened up and can be scraped off with a plastic razor blade. Some residue remains, but this does not matter:

Then I usually glue 4-40 washers to the enclosure as spacers. I use quick setting epoxy:

Then I add some more epoxy on the top of the washers and place the aluminum panel:

Once it is in place, I secure it with carpenter's clamps and a weight for the top right corner, which is not accessible with clamps. This step is crucial, since one essentially only has one shot with epoxy. If you try this at home, make sure that the panel is really in the right spot. Applying the clamps often shifts the panel a bit, i.e. it needs to be kept aligned during the clamping process.

The next step was to put the lid back on. Unfortunately, someone already reattached it once with Gorilla glue and the panel came off again. The glue residue proved very well attached to the plastic hinge and I was not able to remove it.

since the glue residue was flat enough and its thickness similar to 4-40 washers, the situation could be rectified by adding a good amount of epoxy to the residue and more importantly to the regions that were uncoated in between, and placing the lid on top:

Again I secured it with clamps and used a pen to press the hinge upward above the power cord opening. This did the job!

Beomaster 8000: Visit of an Old Acquaintance - Restoration of the Control Panel Lid and a Redesigned Lid Linkage Replacement Part

Oh well...Beoloving can be a bit experimental. When new parts are developed occasional failures need to be anticipated. So it was the case with the part that I designed last year to repair a control panel lid spring retainer when I restored a Beomaster 8000. This part failed during return shipment, maybe due to the package getting a bit hot and my plastic part a bit soft, which let the spring 'escape'. This is how it looked when I received this unit again about a week ago:

To finally cure this issue for good, we decided to purchase a Beomaster unit from ebay. A unit with a badly damaged heat sink became available:

Seems a fork lift drove through it or a similar disaster happened. Miraculously the control panel lid was still intact without any damages. While convenient for the issue at hand, it always hurts to see a Beomaster 8000 go down like this due to carelessness or poor packing for shipment.

Some more parts from this unit turned out to be useful to cure some more cosmetic issues with this unit like the scratched 'Monitor' button

and the broken off control panel lid lock that I replaced with a 3D printed part last year. I took the opportunity to replace both with original parts from the ebay unit:

Beautiful again!

When I put the unit back together after these repairs, it occurred to me that the lid made an ungainly clonking noise when opening. It turned out that the control panel lid linkage that connects it to the motion damper was shifting abruptly from one side to the other in the fixture that connects it to the lid during the opening sequence. I took this as an invitation to improve my 3D printed replacement linkage by making the upper end a bit thicker, so that it fits precisely into the allotted gap, preventing the shifting issue:

I installed it (shown a prototype printed in red for more detail):

After verifying that this cured the issue I replaced it with a black 'production' part since the upper end can be seen when the control panel lid is open:

This linkage, like all my parts, is available to other enthusiasts. Just send me an email or use the contact form on the sidebar.  There is also a video on my YouTube Beomaster 8000 playlist that demonstrates the installation of the linkage.

All good now in the control panel section of this Beomaster! Time for a little test-drive before shipping it back!

Beomaster 8000: Replacement of a Damaged Control Panel Lid Linkage with a 3D Printed Reproduction

The Beomaster 8000 that I am restoring right now is close to being embedded into my Beosystem 8000 for some real life testing in our living room. I usually do that to make sure that there are no intermittent issues before I ship the unit out. Today I put it back together and when I was about to bolt the control panel lid back in, I realized that the linkage that connects it to the damper was installed in reverse orientation, and that one of the receptacles of the linkage had been bent open. When I took it apart it already felt that there was something wrong since the linkage came loose very easily:

Most likely the 'expert' who worked on this unit previously did not know that the linkage can easily be dislocated by turning the damper arm vertical and then sliding the linkage to the right off the hook that holds it in place. He instead used the hot air blower of his soldering station to soften the plexiglass and then removed the linkage...This is the fourth Beomaster 8000 with a damaged linkage that I am working on. When I encountered this issue the first time, I designed a 3D printed reproduction of the linkage. Luckily I printed a few more, so it was an easy task to replace the broken linkage with a working one:

For the record, here is a picture that shows how to position the damper arm to slide the linkage on or off:

Allright! After this I buttoned the Beomaster up and tested it. Everything seems to work now including the Terminal remote. Another 8000 back in service!

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.

Beomaster 8000: 3D Printed Control Panel Linkage

This is the continuation of an earlier blog entry at http://beolover.blogspot.com/2014/06/beomaster-8000-3d-printed-controls-lid.html

I started reassembling the recently recapped Beomaster 8000. It was time to try out the 3D printed control panel cover linkage that I had printed a few weeks ago after finding that the original linkage had cracked and lost one of its hooks. 

I put in the 3D printed part (Makerbot II, PLA, highest density), and it worked nicely - for a few openings and closings - then it popped out at the damper. This meant that my part had a slightly too wide gap on that end, which would allow the damper arm to come loose. I redesigned the part in Inventor with a 0.2 mm smaller gap, and had it printed again. This time it worked very well. The part clicked in solidly, almost too tight. I lubricated it with Ballistol, which resulted in very smooth operation. 

I made a short YouTube video that gives some more info and shows the part installed and in action:

The STL file for the linkage is posted on my website at beolover.com:(http://beolover.weebly.com/control-panel-cover-linkage.html).

Beomaster 8000: 3D Printed Controls Lid Linkage

I just received a 3D printed part for the Beomaster 8000 I am currently restoring. When it arrived I pressed "Programming" to access the controls, and the brushed aluminum cover popped open at an alarming speed, indicating that the damper was disconnected. Once opened the Beomaster up, this was confirmed. Sadly the plexiglass link lost its bottom end and therefore lost contact to the damper that prevents the cover from snapping open. Here is a picture of this sad state of affairs:

So I recently drew up this part in Autodesk Inventor, guesstimating the missing bottom end (I didn't have another 8000 open at that point to take measurements of a complete part). Then I had it 3D printed on a Makerbot II using black PLA: Here is the result:

I designed the holes a bit smaller, and then drilled them out with a 9/64 (right, lid) and a 11/64 (left, damper end) bit. The Makerbot has a hard time to get hole dimensions perfect on this size scale, and it is better to drill the material carefully to get a more machined feel for rotating joints like in this case.

I tested the part on the damper and the lid joints, and it seems to click into place fairly well...when I assemble the Beomaster again, we will see if this really worked (I am a bit concerned that it might disconnect from a joint when using the cover in a routine fashion - I will post an update on that).

Anyway,my fun with 3D printing continues!