Okay guys, I'm in trouble.

A while back, maybe about a month ago (just now getting around to this..), my beloved BeoMaster 3000-2 made two distinct "pops" and now, the only thing I get out of the right speaker is a constant low rumble.

Is the right channel gone for? Fixable?

It was connected to a pair of BeoVox S45-2 speakers and I have confirmed that both speakers are fine, it is the receiver.

Help! Save me, save me!

Thanks, Ev

There is a switch marked "TEST" at the rear, I think it was on the right-hand side. Try flipping that up and down a few times, it might be oxidized and causing a missing channel.

Okay Ill grab a speaker and give it a whirl... one sec!

I gave it some good exercise, no luck. Same low rumble. I turned the unit on in test mode and it was silent.

Next idea?

I'd say, there is a rumble so something is being amplified, the 3000 is still working in a way. I take it you already replaced all electrolytics?

I would take out the multimeter and compare voltages at transistors vs ground between the working and the broken channel, starting at the preamp. Be careful not to short anything!

Good luck!

Good thinking!

The unit has never been opened. Its the same as it was when it left the factory back in 197X. I was so proud of it, unserviced and sounding absolutely superb!

I will try and get inside tomorrow.

What is the best grounding point inside these things?

 

 

Evan:

The unit has never been opened. Its the same as it was when it left the factory back in 197X

That is great (beautiful even!), but in that case, I think you should really put in new electrolytics, these can cause the weirdest faults after 40 years of life because they dry out. If it hasn't caused this fault it will probably cause an other fault any time soon.(Cap kit from Dillen?) It will improve/refresh the sound of the amplifier too, especially if you replace the big decoupling caps too!

If that doesn't help, try the measuring. There is probably a black wire in there somewhere that connects the ground of one PCB to another, I like to use those but any ground point will do, find one you can easily and solidly clip your multimeter to. Never been inside of a 3000 so I can't be much help here!

The BeoMaster 3000 does not have the red capacitors that give problems, they are the same make as the red ones, but they are grey or orange. I have never had one of those fail. 

You could try to make a recording on a cassettedeck from the tuner of the BeoMaster. If the recording turns out all right on both channels, the input of the BeoMaster is OK, and the problem is somewhere between the input selecton and the speaker socket. A simple way of testing the input selection without measuring!

I've never been inside one of these either! I think if I open it up I will recap, I don't want to have to open it up twice. Now, to find a cassette recorder.... Do I even own one of those?! By the way, that tape idea is a genius idea!

Ok! Welcome back ladies and gentlemen!

I have a 4 day weekend so I thought I would try and get this project going again and hopefully get a little progress made.

I just removed the wood panel and I can confirm that this unit has never been opened ever before. I happened to look back at the inside of the wood panel and found an unopened yellow envelope glued to it! I sat and stared at it for a while hoping it was money or something but what I found was just as good; an unused, unseen and untouched instruction diagram (part no. 3523053) in perfect condition with no loss of color (as if it would fade in the dark) and absolutely stunning. After looking through the on-site service manual I see that this is regular practice but I've never seen this before. The feeling was very similar to finding the original build sheet to my 1971 Chevrolet wedged between the seat cushions! I want to frame this thing.

I feel I can trump that! I have a Beomaster 4400 which had sat in it's box as un-sold stock until the day I opened it up a few years ago! Complete with a U70 leaflet, the original instructions and service manual (and the little plastic tuner preset clip!

Hope you get the 3000-2 up and running properly. I have one which has been sat in pieces since I used it as a donor unit for my Beomaster 4000. Shame, as I think the 3000-2 is actually a better looking amplifier...

Well shoot Alex, way to ruin my good mood!!!

The 3000-2 is definitely my favorite amp out of all the ones I own. Mine is rosewood and is in near perfect condition. Don't know how I'm living without it really!

I like the 4000 too, pretty much all the slider systems!

So I was flipping through the service manual last night and I found the explanation of the speaker IN sockets. But it didn't fully help me understand.

Can someone summarize the proper use of this feature and benefits? thx

The Speaker IN is for connecting an extra amplifier to your main speakers.

An example. You own a Tape Recorder with a build in amplifier (for instance BeoCord 1600). You can connect the speaker connections of the tape recorder to the Speaker In of your BeoMaster 3000-2. If you switch Speakers 1 off on your BeoMaster 3000-2 with the switch on the front of the BeoMaster, the Speaker 1 connection is connected to the Speaker In connection. So now you have connected your speakers to the amplifier of the tape recorder. And of course you can also connect any other piece of equipment with a build in amplifier in this way!

So, the volume control comes from the external source?

Can the Beomaster manipulate any part of the input?

The volume control of the BeoMaster does not work, you have to use the volume control of the external source. All the BeoMaster does is connect the Speaker 1 to the Speaker In connection. The BeoMaster doe not even have to be switched on.

This is actually really good news, great even. I have a surround sound and my 3000-2 with s45-2s together in the same room and its a bulky mess in a tiny space. This will allow me to combine the front left and right channels. So now I can get rid of a pair of speakers in the front and just have my beovoxes run double duty. Fantastic!!

The Beomaster 4000 works the same way with regard to the speaker inputs. Did you find any dead bugs etc inside the 3000 when you opened her up. You will be surprised what you will find inside these things as you move forward.

Eugene:

The Beomaster 4000 works the same way with regard to the speaker inputs. Did you find any dead bugs etc inside the 3000 when you opened her up. You will be surprised what you will find inside these things as you move forward.

I love the 4000, are you going to sell one soon?

I haven't found anything but a little dust and some finger prints on top of the power supply box. I haven't yet looked underneath any of the PCBs, so there might be some stuff still lurking underneath.

Finally, summer time has arrived and after a huge hiatus, it is time to bring my 3000 back to life!!

I'll make a pictorial out of this with my repairs.

Right now the BM3000 sits on the kitchen counter with the lid off and I am itemizing the electrolytics on the amp board. Next to me is a copy of the service manual awaiting my notes!

I can't wait for this thing to be playing amazing sound once again

The BeoMaster is on the counter and here I have removed the six screws on the bottom to get the bottom cover off.

After getting off the bottom plate I can have my first glimpse of underneath.

With a unit that has never been opened before, it is interesting to find such a lot of black goo all in one place.......

I think I have already found the culprit to my problem!!!

Much like the capacitor picture posted in Rich's "BM4000 Down!" thread, the power cans in my Master have failed.

The two smaller caps have failed and I'll assume the largest has also. I was actually quite suprised mine were faulty. From above they looked flawless. I wish I had a meter that measured capacitance - would be very interesting.

So my first questions to the professionals:

1) Should I desolder the caps or is applying heat to unstable caps not safe? Or should I just clip the wires? Never encountered something like this before and want to be safe.

2) What are [or who makes] good replacements for these three caps?