I´ve just bought another Beosystem 5000, that came up for sale cheap. It stood unused for some years, and was described as "non working". 

The main reason for buying another set was, that it included a Beogram 5005 (my other system is a Beogram 5000 with MMC4) with a MMC1. The little belt was laying loose in the cabinet, and after fitting that (and some cleaning and lubrication) the Beogram plays beautifully. 

The set also came with:

Beocord 5000 type 4921

Beogram CD50 type 5111

Beomaster 5000

MCP 5000 (in better condition than my current one - mint)

B&O AUX Expander

Two complete sets of Master Control Link 82 (panel, box, manual, wall bracket) - are these worth anything? I´m not gonna use them.

Complete set of manuals 

Original sales receipt (08/1985)

Manuals for Beovox Penta and Beocord VHS91 (both Danish) and a brochure from the mid-90´s.

Current status is:

Beogram: cleaned/lubed, works great.

Beocord: cleaned, works great

Beogram CD: belt is broken, but plays. Will need cleaning and lube.

MCP: cleaned, works great

The Beomaster was the worst one, and the reason for this thread. The ribbon cable for the front panel was completely broken. I´ve replaced the cable with a ribbon cable from a floppy drive, and that now works fine again. However, the sound is terrible. It sounds disorted no matter what input is used, and even with the volume cranked up to 50, the sounds equals level 26-30 on my other Beomaster 5000. So I guess something has gone tired, and this is were I need help. 

Is it some worn out capacitors? There was a relay next to the transformer, that looked a little tired, so I cleaned the contacts, but that didn´t make any difference. 

Any help and tips would be highly appreciated.