geearr wrote:

Thanks Eugene

Pleased to hear that you are watching - I can always do with some help from someone with your experience.  Have you worked on the "quad" before?  If you answer "yes", be careful because you will be inundated with a stack of questions.

Regards

Geoff

No Geoff I have not worked on a quad before and considering all the time and patience needed to restore one of those beasts experience tells me to stay away. I do like the innovations you used to put it all back together. A lot of fiddly tweaky reassembly.

Interesting that you used the "tapping" method to find fault on the tone control board. Done that myself a few times on the Beomaster 2400 tone controsl. Not very technical or scientific diagnostic but it sure beats the hell out of dragging out the sillyscope and soldering up test lead and all that time consuming business to isolate one small component failure.

Now that you have her running again I suppose its time to sit back and enjoy the sound for a bit.......

but at some point are you going to open her back up and replace all the reamining original electrolytic capacitors ?

Hi Everyone

As I mentioned yesterday, this project is nearing completion.  The Beomaster 6000 quad has now been re-assembled and will be put to one side while I catch up on all the other tasks that I have ignored over the last few weeks.  So what are my latest conclusions about the “quad”?

Well, I have taken an old unit that wasn’t even making a noise and returned it to a condition where all four channels are producing a good sound.  For me, that was the primary objective of all this work and I have achieved what I set out to do.  Very satisfying for a rank amateur.

I have learnt that this Beomaster is extremely complex and difficult to work on.  While trying to cram everything inside that tight box, I was always concerned about possible short circuits.  Every time that I switched it on, I was expecting a flash of some sort.  It will actually be a welcome relief to work on something easier for a change and see my pulse rate slow down.

It has been slow and painstaking work and I can understand why Martin inferred that there wouldn’t be too many people who would be prepared to undertake this assignment.  The man hours are going to be very high and at times, progress is very slow indeed.  I’d hate to be paying for it by the hour!

I have always liked the appearance and design of this Beomaster when I have seen it in the sales brochures and magazines.  However, in reality, those horrible wear patterns on the push panels and the aging marks on the black display panel do make it less attractive when you look at it closely.  Recovering that wonderful, original pristine condition would be a mission impossible for me.

My first impressions on the sound quality was that I was happy with it.  One day, I will set it up properly for ambiophonic reproduction and give it a good test but in the meantime, it still sounds good on my “low fidelity” work bench.  I don’t think that I will ever be able to get a quad source to evaluate - but one never knows.

The first pass on this Beomaster has fixed a number of issues but there still remains more work to be done.  So far, I have come up with the following list.  Most of these tasks are fairly simple but there are some that I would appreciate more help with.  Here they are:-

The “power on thud” must be fixed and I am still not certain which components I am going to have to replace.  This is probably the area that I least understand and require most help.  I plan to investigate it more thoroughly next time the machine is open.

The front / rear balance indication is not working but I do hear the motor turning.  This probably means that there is a wiring loom jammed on top of the drive wheel.  Should be very simple to sort this one out – after all it was working when the cover was off. 

The tuning indicator is very far out, probably about 50mm from the correct position.  I am not sure how it got in this situation but it is normally fairly easy to reposition the clip on the string.

Some of the push panels are not acting as good switches.  I hope that it will be possible to improve the sensitivity of these, after all, only a delicate touch should be needed, not a high pressure thumb print!!  Has anyone tried to address this problem on these push panels or any other similar machine that uses them?

P5 tuner is definitely broken but I wasn’t able to get any access to the trimpot.  My first impression was that it was a sealed unit but I could be wrong.  Can anyone advise me how to successfully dismantle this assembly, there are no clues at all in the service manual.

There are several pinholes in the black mask on the display panel which let light through and detract from the appearance.  A touch of black paint on the underside should fix that up fairly easily.

The cabinet requires a lot more TLC to bring it back to a superb condition.  This is just fiddly, time consuming work that can be done at any time – but in the end, it will be well worth it.

Well that is my short list, not much is it!  This Beomaster is almost back to being a useful piece of audio equipment.  Here it is ready to go into hibernation for a while.

My thanks go to all Beoworlders who have been supportive of this project.  I hope that you found it interesting and one day perhaps, this thread might be of use to someone else who is also working on the “quad”.

Best regards

Geoff

Cant really see in detail the wear on the push panels, perhaps what I am looking at is 30+ years accumulation of oil dust dirt and grime, then add oxidation to the mix and your left with a dull dirty looking control panel.

If thats the case the good news is that it will all clean up nicely with the right soap and some patience and a bit of elbow grease. The tarnish can then be remove with a coat of brasso or similar metal polish.

The heavy top layers of surface grime will pull up quckly then it will be a matter of lifting out the deep ground in stuff. Repeated application of a suitable grease cutting detergent and a soft nylon bristle brush will do the trick.

Hi Eugene

Getting good photos of this machine has proved difficult for me but the photo below shows what we are up against.

This was in the as-received condition with heavy wear on most of the popular keys.  One of my first steps was to use the standard B&O cleaning recipe, ie water with one drop of washing liquid - applied on a damp cloth.  All I can say is that only made things worse and all of the worn areas expanded dramatically.  It looked as if there was a layer of lacquer that was peeling off and the more you rub it, the worse it gets.  My only solution was to rub the whole lot off, back to fresh metal but I fear that the original factory finish has long gone by now. 

Patience and elbow grease I have already used but now I will have to experiment to find a finish that is both durable and attractive.  At the moment the keys do look quite nice but I am not sure how long that is going to last for.

Regards

Geoff

You can always have the keypad re-dipped in annodizing solution.

I am not entirely sure these panels were anodised originally? I know it is brushed metal and there certainly is a layer of lacquer applied, which I would think means there is no other protection from tarnishing which anodising would surely perform!

@Geoff there have been threads where people have tried refinishing Beogram switch panels which are essentially the same as this model. Try searching if that helps! I have to do the same on a couple of Beograms but these are currently on the 'to do' list!

Most Beo alu panels and buttons are anodized, what I have done is using this white

Step1 wrote:

@Geoff there have been threads where people have tried refinishing Beogram switch panels which are essentially the same as this model. Try searching if that helps! I have to do the same on a couple of Beograms but these are currently on the 'to do' list!

Thanks Olly, I intend to read through all of the information that must be available somewhere.  Likewise, this is going to take a low priority down towards the lower end of the "to do" list.

Regards

Geoff

Søren Mexico wrote:

if I get down to the pure alu I go all the way until the whole surface is clean and even, then clean with acetone, use clean gloves, dont touch the clean surface with your fingers, emidiately after cleaning with acetone, spray 1 time with clear polyurethane, let dry and give it 1 or 2 more coats.

Thanks Soren, I appreciate your ideas because those are the same lines that I have been thinking along - a good clean followed by a lacquer finish.  That should work OK.  The big hassle is going to be masking off the rest of the kit.

Regards

Geoff 

Thee BEST results on refinishing these keys I have ever seen: