Thanks Martin,
Yes, I bought this in Sweden and I think it likely it was originally sold here.
I do hope so much I will be able to make it sound. I am very curious about it's sound. Not sure I can pull this off by myself, but I will try.

It looks like in this photo below (not mine, mine is even more broken). I have to fix this somehow. Thinking about it. Spares is probably not to think of. I have been thinking about visiting a hobby/model building store and see if they have something with which I can build up a frame for the transparent scale and have it attached.

I also wonder if anyone could advise about the zener diode ZF 9.1. I must purchase a new one. Swedish Elfa has two variations, 9.1V 3W or 9.1V 5W that I consider. There are also 1.3W versions. The service manual says "the electronic protection circuit will operate at a current drain of approx 4 W".. Is that what I should base this decision on? A simple calculation gave 3W, but I am not sure about this. The Wattage shouldn't affect the performance of the diode in any other way I believe?

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Googling ZF 9,1 tells us it's a 500mW diode.Use a 1,3W.

I did a quick calculation of the current  through the zener diode and ended at about 8-9mA through the transistor and 10mA through the 1,8k resistor.

18mA in total,which gives a total power of about 170mW in the zener diode.

Rolf, so grateful for your advice! My calculations were way off, as suspected.

Capacitors ordered from Mouser. Zener will be bought at Elfa.

Today I bought a second BM1000. For reference..
Together with it came a pair of S45 speakers. They are in good condition cosmetically but the foam is bad and the need restoring. Do you want them? I give them away. I live in Stockholm Sweden. Space is getting scarce here. I hope they can come to a good home.

This BM1000 was supposed to work. But before plugging it in I took a look inside. Someone has been tampering with this one as well. The on/off and the mono keys have switched place. Some screws were missing. The fastening point on the top of the cabinet was broken. The schematics are missing. But worst was the horrible dirt. Thick dust. But not "nice" dust that you can blow away, but sticky, greasy dust. After some preliminary cleaning with a brush and compressed air, I just had to plug it in to see what happened. And it worked! 😁 I have never heard a white keyed Beomaster 1000, but I had a feeling I would like the sound. And I do! Perhaps I have fallen in love.. Connecting it to a pair of Wharfedale Dentons (original early 70'ies or late 60'ies, newly restored) and a pair of Beovox 2702's (also newly restored) it really sings! I never made these speakers sing before like this. I even considered selling them because with my Tandberg equipment they just sound sad, dry, thin and hollow. How come this little receiver from 1969 can sound so "fat"? I love it!

Some people say this receiver is not for everyone, that it has a special sound. What do you think? For me, who is allergic to modern "analytical", sterile sound with treble like sharp glass that cuts my ears.. perhaps this is just what I was looking for. And this even without me having changed one component (in spite of it's age, it sounds like this.. What if components would age like a good wine, to mellow..).
I also have an unrestored black key BM1000 (not tested). I wonder how they differ in sound?

Leads me to the next question for you gentlemen and gentlewomen better versed in electronics than me. My plan is to keep this one as untouched as possible, while I restore the other one totally (every capacitor will be changed, at least all the electrolytics, I think I have 55 pcs waiting..). But is there anything I might want to do to avoid a disaster? I think, maybe I should change the two 2200uf 25V capacitors that I believe drives the amplifier? And perhaps the 2200 50V power cap? To avoid speaker blowup in a capacitor meltdown scenario? Now, I dare not use it for everyday enjoyment. But I don't want to tamper with it too much.

Oh, one more thing. Perhaps someone can advice, how to best clean away the oily greasy dust. See the photo. Isopropanyl alcohol, can it be used? Just bought some. Risk of destroying something, on the board for example? Perhaps you have better ideas. The greasy dust stuck on the transformer is specially bad and hard to remove.

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I have always cleaned mainly with IPA, (isopropyl alcohol) but I always take the unit down to the nearly last screw, even if I have to desolder, on hard to clean metal parts sometimes I use acetone (careful may strip paint and destroy plastic), rusty pieces I leave overnight with a thin oil layer and then clean off with acetone ( if not clean, use abrasive pads), then a thin coat of oil.

Some of the guy guys here recommend Windex (window cleaner) some of them mix it with IPA some use it directly and then clean with IPA afterwards.

I have a bottle of Windex here and will try it out on my next object.

I have never heard a white key BM 1000 but the sound should be special because of the germanium TRs

Good luck

Even if the BM works, I would change all the electrolytic caps, here a pic from my BL 5000 of what happens when they start leaking

I wonder where does the grease go after applying IPA. I know the IPA evapourates, but the dirt..?

So IPA does not destroy the board or any other components and can be applied liberally I understand.
Cleaning it will be an interesting project too.

I hope to keep this one as original as possible, until I can compare the two.. But I understand they both need new capacitors. Thinking of that, if you change all the capacitors, isn't there a risk that the original sound is changed? (However on the other hand, all the capacitors are old and may not perform optimally, I know). What performance can we expect with modern day components? Has anyone noticed differences with different types/makes of the exactly same spec components? For the first BM1000 I bought all new capacitors, mostly Nichicon Fine Gold type.

You wil have WASH to get the grease off, it will have to drain off with the IPA

The two 2200uF capacitors on the main board don't "drive" the amplifiers, they are the output series capacitors.
The 2200uF filter capacitor in front of the transformer is a nasty one, it is known to go with a terrific bang, leaving a huge mess.
I would replace the three.

Note the polarity of the filter capacitor - remember this Beomaster has positive ground.

Martin

The three largest capacitors has been changed. The inside cleaned.
It works! The sound is still nice, in spite of my molestation.
It was difficult. Specially soldering those points where legs of the caps and several cables go together was difficult.
I'll leave the restoration from now to pro's. Too much for an amateur like me.😕 If you saw my solder joints you may ban me from this forum.
It was fun though, studying and preparing.

Someone who could restore them for me?!

I now have three machines, two white keyed and one black. And I have sets of components for restoring two.
I have become a complete fan of the white keyed Beomaster..
They white ones all have their own individual cosmetical problems. I would love to have one in mint condition, or nearly mint.
What do you do when the scale front rail has broken off, like in my earlier photo? I don't want to scrap it as a spares machine, I would hate that, and it is in nice condition except from this. Was thinking of building a new front, but I am not really good at such things.