Beomaster 5000 Type 2323: Assessing a new Beomaster restoration

After what seemed like a long period of Beogram restorations I have retooled my workbench to do some Beomaster restoration projects. I have some Beomaster 4400 receivers to tackle but before that I decided to restore a nice Beomaster 5000 Type 2323 for an original Beosystem 5000 system owner who previously sent me a CD50 to work on.

This Beomaster 5000 receiver is in nice shape but stopped working this year.  It is actually quite impressive that it was still functioning up to this decade considering the Beomaster was produced thirty-five years ago.

I love the way Bang & Olufsen designed these series of cabinets.  Simply moving two screws upward at the back of the cabinet releases the catches that secure the cover.  When the screws are fastened in the up position the cover can slide off.

Here it is with the cover removed.

There is a little bit of dust but the Beomaster inside is surprisingly clean after thirty-five years.
You can tell it was always in a good environment for electronic equipment.

Flipping the unit over I removed the bottom panel.

Now a flip back to the top side where the components can be removed for examination and restoration.

Another nice feature of this receiver cabinet is how modular it is and how easy it is to get to components.  The top PCB (PCB 1 - AM/FM board) unbolts and flips up to a service position and reveals the preamplifier board (PCB 3) underneath.

At the very front of the Beomaster 5000, behind the display panel, are boards 7 (Display-right), 8 (Display-left) and 9 (Remote control).

With the front panel pulled out of the way the Microcomputer board (PCB 5) can be accessed and removed.  It is held in place by two plastic holder pieces that pull out from the top.

After the plastic board holders are removed the PCB 4 connectors can be disconnected and the Microcomputer board removed.

There are four electrolytic capacitors and a 3 volt lithium battery that will be replaced on this board.

The next component assembly to remove is the fan assembly.  Yes, with the compact size of the cabinet and the fact that the Beosystem 5000 components are expected to be stacked on top of each other, B&O installed a temperature sensor and a cooling fan.

The next assembly to remove is the plastic housing for cooling air to flow to the output amplifier board.

That assembly can be a little tricky to get opened up as the two large power supply filter capacitors have to be rotated to uncoil the three wires they are connected to.  When the wires are uncoiled there is enough room to move the plastic housing out of the way (and to remove the two filter capacitors for replacement).

All of the boards that have electrolytic capacitors I will remove are accessible now.

The Preamplifier board is easy to get to.

So is the power supply/output amplifier board.

You can see in the photo that the large relay on the power supply board looks a little charred inside.
That is typical on these amplifiers. After years of arcing during power switching of the Beomaster the relay contacts get pretty charred. I will replace this relay with a brand new one.  There is a matching speaker muting relay on the Preamplifier board that I will replace as well.

Here is the power supply/output amplifer board removed and ready to be worked on.

Now I have to make sure I have all the necessary replacement parts (there are about 71 capacitors to replace)...then I can start on the restoration tasks.