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Late Beogram 4002 and the 4004 (Types 551x and 552x), which have DC platter motors instead of the earlier synchronous AC motors usually suff...

Sunday, December 31, 2017

Beomaster 8000: Beosystem 8000 Mate to the Beogram 8000

Now that I have the Beogram 8000 turntable restored where I can enjoy it I can begin work on the Beogram's receiver. The owner of these two fine components is an original owner of a complete Beosystem 8000 set. I can gladly say I am also in the Beosystem 8000 club although the Beosystem 8000 is actually referenced as the Beolab 8000 by the Bang & Olufsen 1981 catalog. At that time the system consisted of the Beomaster 8000, Beocord 8000, Beogram 8000, Beovox MS 150 and the SC80 cabinet. When the Beogram 8002 and Beocord 9000 came out the B&O catalog called the system the Beosystem 8000.  There are actually two versions of the SC80 cabinet for the components. I have the first generation cabinet. The later cabinet has open ends instead of the closed ends my cabinet has.






















I like to refer to the system as the Beosystem 8000 since B&O later reused the name Beolab 8000 for one of its powered speaker towers.

Here is the Beomaster 8000 for this next project. It is a Type 1903 and is one of the later model units.



This Beomaster is in excellent cosmetic shape although there appear to be some missing control buttons on the inner programming panel.






















It looks like the button board is loose so the button covers are probably loose inside.
Here are some more pictures of the exterior before I open it up.























Beautiful. Now let's open it up. The control bar pushes down and slides to the left where it can be removed. Underneath the removed bar are the first set of screws to remove to open the receiver to its service position.

The control bar that was removed should have three brass springs to keep the bar in place. It is common for those to be missing on these Beomaster units. They are easy to fall out and get lost by technicians working on the receiver.

This Beomaster has two of the three springs.
















The first one is a small spring that is all the way on the left. The other two are wider. There should be two of the spring shown in the next picture.









I have seen requests by other Beomaster 8000 owners looking for these springs so maybe it is something we can look into making a replacement part for.

Here is the Beomaster opened part way into its service position.























The metal box is the microcomputer for the Beomaster. It is the newer box design with the easy opening lid so that is nice. Here is the receiver fully opened up.























Aside from some dust everything looks really good. I have seen some Beomaster 8000 units where the boards are dark from heat. There are no signs of any excessive heat on this unit. All of the boards look great.

The door for the inner program panel is all intact and the door hinge lever is still in one piece. It is common for that lever to be broken. If that had been the case we have a Beolover 3D replacement part available.


Here  is the damping component the door lever connects to. It has damping grease inside that is often deteriorated and leaking out by now. This one appears to still be good but I will check it out more thoroughly later.



The missing button covers were indeed loose inside the board assembly. Once I removed the plastic cover they fell out. The cover has the beginnings of a slight stress fracture. It isn't bad so I will re-enforce it underneath with a flat piece of plastic and some epoxy. Perhaps the stress fracture occurred the same time the button board became loose. It is in the same area.






















The Beomaster connector panel for source inputs is in good shape. All of the DIN jacks look good.






















When I begin the capacitor replacement I will probably start with the hardest ones. Those are the four big reservoir capacitors for the left and right channel ±55 VDC rails.





























Modern 10,000uF power supply capacitors are in a smaller footprint so I will use the Beolover 3D printed adapter for these replacements. The adapter retains the footprint of the reservoir capacitors so they fit exactly as these original capacitors do.

Time to rest up before starting the recap work.

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