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: First Assessment and Initial Damage Report

Today I extracted the newly arrived Beomaster 8000 from its original box. After I put it on the bench I opened it up. I usually do not turn them on before I rebuild the output stages to prevent burn out of the transistors due to open circuit quiescent current trimmers. I always enjoy my first look into a new Beomaster 8000! Always some new challenges. No different with this one. It came with the information that the frequency display is too bright relative to the others, and that the control panel cover latch is broken. What I found was pretty stunning...clearly another amateur restoration effort gone wrong. Here are some pictures:

The control panel latch lost both ends...pretty amazing, never seen anything like this. Raw forces must have been applied. Also note the gaps in the panel about half an inch to the right and 1/8th to the left...very strange!

On to the display. The frequency display has clearly been tampered with. Note the glue smeared along the upper end of the red cover. Probably implemented the wrong LEDs in an attempt to cure a few dead segments. Or the amateur simply did not realize that modern SMD LEDs are brighter than the original ones, and that one needs to replace them in all displays and then needs to adjust the brightness to match the original appearance...I am curious what I will find underneath this display cover!

 Even more strange is the 'melted' bottom clamp that holds the display in place (probably used his soldering iron trying to pry it out...I am shuddering while imagining this dilettante in action). He must not have realized that one needs to take out the entire display bar to get them out without doing damage.

I also found the usual somewhat browned emitter resistors in the outputs, indicative that new quiescent current trimmers are of the order:

And then there may have been a u-processor board upgrade for Christmas in 1994:

After all his great 'work' the dilettante also did a rush job putting the Beomaster back together:

I found this cracked control panel mounting tab...even the bottom part where the screw is held is cracked...

also the control panel cover damper linkage was disconnected, explaining the undamped cover:

And finally: Loose screws that hold the heat sink cover down at the front:

O.k...enough for now...tomorrow is another interesting Beolover day!