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part needed for the yamaha RX-330 stereo receiver.

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anon125

New Member
the input selector has four positions, a rotary switch.
sometimes it make contact but not usually.
do you think it is silver contacts that just need a clean? (what with)
or is it a replaceable part.
yes it is old, but we like it - when it works!
thanks all.
if this is the wrong forum, please let me know the correct one!
 

audioguru

Well-Known Member
Most Helpful Member
I retired my RX-300U Yamaha receiver because its selector switch contacts were not reliable, even after using contact cleaner. I think after many years the housing of the switch wore out so that the switch would move past where it makes contact.
Kiss it goodbye then bury it.

I am back to using my 52 years old HH Scott stereo receiver. Its switch contacts also become intermittent because they are silver but contact cleaner makes it work well again for a couple of years.
Everything I made used gold plated contacts for low level signals that cost the same as silver contacts. They never became intermittent.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Try a SMALL squirt of WD40 on the contacts, it's far superior to 'contact cleaner' for such purposes.

We've used nothing else for servicing purposes for over 30 years now, never had a problem with it, and much better results.
 

audioguru

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WD40 is a perfume that quickly evaporates, leaving behind some lubricant that attracts and holds dirt. The film of lubricant is an insulator.
My contact cleaner washes away and removes the stuff left behind from WD40.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
WD40 is a perfume that quickly evaporates, leaving behind some lubricant that attracts and holds dirt. The film of lubricant is an insulator.
My contact cleaner washes away and removes the stuff left behind from WD40.
As always in this case, you are 100% wrong :D

The lubricant is what keeps the contacts clean and well lubricated, and promotes good contact.

The original switch contacts as it was made included lubricant, so it needs to be replaced.

Instead of 'making up' theories as to why it doesn't work, perhaps you should simply try using it.
 

audioguru

Well-Known Member
Most Helpful Member
Silver contacts should never be used for low level signals that have no DC (dry) because silver tarnishes (corrodes). The corrosion conducts poorly and/or rectifies the signal. Silver is good for high current high voltage contacts. My contact cleaner washes away the corrosion. There is an expensive contact cleaner Deoxit sold in music equipment stores that experts say works well but I have never used it.
Gold plated contacts are used for dry low signal level contacts because gold does not tarnish.
 

anon125

New Member
I assume replacement parts have not been available for decades!
surely something has the correct number of contacts!
thanks all
 

vtech

Active Member
[QUOTE=...... There is an expensive contact cleaner Deoxit sold in music equipment store...

I'd vouch for Deoxit from Caig laboratories. They now have several types and it may be more expensive but it is definitely worth it.
I have been using it for decades. Anything from Consumer Electronics to Automated test equipment applications.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I assume replacement parts have not been available for decades!
surely something has the correct number of contacts!
thanks all
Often such switches were specially made for the item in question, at one time though you could buy switch 'kits' which you ordered and assembled yourself (no idea if they are still available?), but the problem was often the physical size.

However, as I said, a little squirt of WD40 will most probably cure the problem, at little cost.
 

spec

Well-Known Member
Most Helpful Member
the input selector has four positions, a rotary switch.
sometimes it make contact but not usually.
do you think it is silver contacts that just need a clean? (what with)
or is it a replaceable part.
yes it is old, but we like it - when it works!
thanks all.
if this is the wrong forum, please let me know the correct one!
If you can find a good quality replacement switch for your old switch, the best bet is simply to replace the switch. In addition to dirt/corrosion, switches often wear out and the contact material, whether silver or gold, has worn away and all that is making contact (or not) is the base material. Not only that, but the indent mechanism wears or gets loose and contact tension lessens with age. On top of that, some switches are simply junk from the start.

As has been said, you used to be able to get switch kits- I had a box full but long gone- so that you could replace most parts of rotary switches. But, if you can't get a new switch from the original manufacturer, you can still steal wafers from another switch if you are lucky and you can find a switch with equivalent wafers.

Often changing a switch transforms a piece of equipment.:)

I once changed the input selector switch on an otherwise reasonably good audio amplifier; not only was the sound quality better, probably because of the better contacts, but the amplifier felt more solid. The owner could not have been more pleased.

spec
 
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dr pepper

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Different people will no doubt have their own methods.
I use a cheap version of wd40 for cleaning reall ybad switch contacts on vintage equipment, the cheap stuff seems to be good for cleaning, I use some of this then blast it clean with carb cleaner, then put a few tiny blobs of clock oil on the moving parts.
There are different schools of thought on self cleaning contacts, I dont think however that a input switch will be able to self clean as the current will be too low, unless the clean action is mechanical instead of electrical.
 

Tony Stewart

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I agree with WD40 et all .

It saved my life during a winter storm coming thru Winnipeg when there was nothing there but farm land from Univ with 2 ft snow drifts and -30'C weather and late at night with no traffic. and no cell phones in the mid 70's.

My distributor was arcing from moisture and the WD40 displaced the moisture and carbon enough to prevent arcs on cap and the engine started up and I made it home. I also use it for low V electrical contacts, and it prevents oxidation with enough contact pressure and roughness to break thru the film. (maybe Guru's experience had contacts which were too smooth)

I bought some continuous rotary switches a while back from D-K where you can put a mechanical stop to use as many positions as you need. Standard 1/4" shaft thread-mount. See if that matches your size. ( probably too big)

check here
 
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dr pepper

Well-Known Member
Most Helpful Member
A straw on the can ought to squirt some crud in there ok.
If you use the same input all the time have you thought of just linking it out?
 

spec

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Most Helpful Member
First impression is that the switch is a special that is screened for minimum hum and noise pick up. Can you see any way to remove the metal can around the switch to allow access to the contacts, or is the whole thing one piece?

spec
 
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