Hi all,

 I'm refurbishing my 3000-2 after being stored many years. The push switches were intermittent at best or just not working, sliders noisy, and most of the lamps were out.

I tried just contact cleaner (LTV) at first which improved the switches somewhat but still not satisfactory. Then I tried contact cleaner plus lubricant from Radio Shack and that did it. The switches and slider pots now work as new, solid contact and smooth action. It may not be ideal as it leaves a residue that might collect dirt, but I suspect it will be good for years at least. I'm impressed with the quality of the switch mechanism. It really is good as new.

Dillen (Martin) supplied the lamps and a cap kit. It turns out my meter uses an axial lead lamp, like a resistor. Martin only had the other type meant to plug in like the other lamps. It's too big to fit in the space in the meter, but I was able to bend the wires straight and carefully cut and remove the plastic plug, just beyond the bulb itself, which encloses the wires. I then bent the wires in outward U's starting at about half of their length, and soldered the wires to the terminals such that the lamp hangs vertically, upside-down, between them, in just the right spot.

While I have the faceplate off I'd like to clean the backside of the sliderule plastics but I'm concerned about dismantling them. It looks like the aluminum endcaps are held by a small tab folded over. Are the tabs liable to break if bent, or is there another way to get the sliderules off?

Thanks,

gary

Once again, welcome to Beoworld ! 

Good job so far !

The sliders are best left undisturbed. The little tabs will break so better leave them unless you absolutely have to dismantle them.

In case a tab breaks, you can glue the partts together but that will be the last resort and own't be easy to take apart again if the need should ever arise.

The axial lamp is a problem that I'm still working on. I do have a couple of spare meters in stock with the normal socket though and they are failry easy to replace. Of course this will compromise originality so will also be a last resort. It sounds like you did a great job with yours though.

The contact cleaner will probably not provide a solution for years. Weeks or months maybe but of course you could be lucky.

Martin

Martin:

Have you found a long term solution for cleaning the sliders?

I've got very noisy sliders on my beocord 8000. Cleaning with contact cleaner cures it for a few days and then they are scratchy and noisy again.

Derek 

gary:

I tried just contact cleaner (LTV) at first which improved the switches somewhat but still not satisfactory. Then I tried contact cleaner plus lubricant from Radio Shack and that did it. The switches and slider pots now work as new, solid contact and smooth action.

 Hi.

I have a Beomaster 3000 (same as the 3000-2 with just some small changes). It too had noisy sliders and the switches were all dirty - it was impossible to get both channels working without fiddling the switches on and off. In my case the contact cleaner worked - and still works after at least 4 months. I did noticed that the noise came back but after second cleaning or so it has been ok.

I by the way just replaced the caps too! Also good to know about the meter lamp type - sounds that you did a good job with it!

I was also wondering if the sliderulers can be taken off but I didn't wanted to break anything so I let it be - they weren't too dirty anyway. But I would be interested if somebody knows how it could be done!

Martin,

 You may be right about how long the switch cleaning lasts, but the persistence of the lubricant makes me optimistic. I don't look forward to having to take the faceplate off every few months to renew the cleaning!  Is there any other solution? I don't suppose new replacement switches are available?

I'll definitely leave the sliderules alone.

Thanks again for your help. At least it all works great for now!

gary

As you say,the switch is a good quality device (German)

The only permanant solution to the intermittant contact problem is to actually dismantle the switch assembly!!

It can be done,although it needs great patience as you can imagine,but the results are good,and the repair of course lasting.

I've done several (mad or what?) and I only gibber occasionally!

Regards,

Nick

The potentiometers can be serviced in the Beomaster 3000 (and 3000-2 and derivate models) without touching the sliderule controls.

Take them apart and clean it all well. Most important is the contact track that lies along the resistive track. This will have to be cleaned using a glass-hair brush. Rub until its shiny and all oxidation has gone. The resistive tracks can be cleaned using contact cleaner and cotton buds, wipe dry afterwards.

The sliding part inside the potentiometers have little contact points that will also clean well using the above mentioned method.

A little amount of silicon grease can be added to the sliders plastic tracks to add a little smoothness and you will have noise-free potentiometers again for many years.

The row of switches is a different story. They are extremely hard to access but usually responds well to contact cleaner in large amounts. You can add a little contact cleaner first and let it soak and losen up the oxidation for 5-10 minutes and then, with the Beomaster at an angle and on some newspapers or similar, spray large amounts into the switches to simply flush out the dirt. The dirt needs to be removed from the switches rather than shifted around inside.

Martin

Martin,

 I feel a little better, I had done much as you describe to clean the switches. With the faceplate off it is possible to position the cleaner spray tube between the white plastic movable pieces and the stationary contacts to flush them all. I started with the LPS brand cleaner (not LTV as I said earlier) which is plain solvent. Later I repeated with the lubricated cleaner.

But I couldn't actually see all the contacts so I don't know if there may be some dirt remaining.

 Nick, can you describe how far you disassembled the switches? Did you unsolder them?

It took a fair amount of patience just to reassemble the faceplate!

gary 

The switch contacts actually become oxidised with age,and become blackened depending upon the atmosphere the equipment has been kept in.You can measure the increased resistance,so it's no surprise that signal quality is affected.You can achieve a temporary solution with solvents,but need to be careful what you use,so as not to damage the plastic contact holders.Also repeated washing out with some solvents,will remove the lubricant from the mechanism.

Dismantling the switch is "do-able",but yes,you do need to desolder the connecting loom,and then the individual switch sections,which seems quite daunting at first.

The results are really good though,with not only no switching noise,but improved sound through less signal losses.

Regards,

Nick

I can only second what Nick just wrote, you will get the best result this way It goes for all contacts, potentiometers etc. that the dirt and oxidation will have to be removed mechanically to achieve optimum performance.

It's a lot of work if you have to do a Beomaster 3000 and you may want to take a couple of photos for reference on wire colors etc. but it is very rewarding.

I've done a couple of Beomaster 900's and 700's the same way though they prove to be much easier. 

Martin

Thanks Nick and Martin.

It helps to know how the switch disassembly has been done successfully, and that it's worth the effort if/when they become intermittent again. It *is* rewarding, to go against entropy!

Even if it causes the occasional gibber.

gary

Seems like a silly question but what is the best way to remove the face plate? I also am having the problem of only one channel working.

Also, what is the best way of cleaning the switches - is it possible to do this with a spray without having to dismantle everything. 

Finally one more question, what are the Caps you are referring to? As you may gather, I am a complete novice and haven't been able to track down a manual for the 3000-2.

Any help/suggestons would be much appreciated, thanks. 

Hi,  OK switches are all fine. I still have only one channel working (unless in test mode), which was my main problem in the first place. Any suggestions?

Thanks again. 

Swap left and right channel where they go to the amp board. This will tell you if the fault lies in the amp or earlier in the signal path.

Martin