Fixing flaky buttons

I assume you are referring to pcb-mounted momentary contact switches. The best remedy I have found is WD-40. Use the nozzle tube and apply a small amount right to the small gap where the actuator protrudes from the housing. Then rapidly & repeatedly push the actuator about 20-30 times. You may have to apply the '40 more than once. And of course, clean the PCB afterwards. I assume it's the foaming action of the WD-40 that allows it to get to the contacts in the switch. At any rate, it usually does the trick.

Dont do this! Without wishing to start yet another WD40 war, the damaging effects of WD40 on electronics are well documented. The manufacturers of WD40 themselves do not advise applying their product to electronic components.

There are plenty of products designed for the purpose of switch cleaning.

Ron(UK)

Wow, I'm surprised to hear this. And I'm not being facetious. I can only assume that this "war" raged on before I started reading this newsgroup. As I mentioned in an earlier post, I'm new here, just getting my feet wet. And my only intention is to pass along what I thought to be good advice. I would like to hear more about the WD-40 debate (or skirmish), perhaps you could drop a short new post? I would like to hear more. But I would also like to clarify my point. I serviced consumer electronics for 27 years before I retired due to disabilities (3 years ago), and I can't ever recall having to re-service any unit due to the use of WD-40. As I said, use only a small amount of the product, applied right where it is needed. And cleaning up afterwards. We're talking about miniature switches, handling only keyscan pulses from a processor. And I certainly wouldn't expect or recommend using it where higher power circuits are involved. It's just that I can't visualize a small amount of WD-40 on the surface of a pcb causing a problem.

It doesn`t so much damage pcbs, as certain components i.e. electrolyic capacitors where it mirates up the legs and damages the seal leading to failure. It also accumulates a residue beneath other components such as i.c.s which can cause all sorts of spurious problems.

There have been several 'heated debates' on various newsgroups over the years, culminating in one regular and respected poster, Lord Valve actually emailing the manufacturers of WD40 for clarification as to whether they approved of their product being used on electronic components. The reply was a very definite NO.

A search of dejanews for WD40 should pull up plenty of interesting reading - you may need a stiff drink first mind.

I realise that your advice was made with the best intentions, and that you advised a sparing amount of WD40 be applied, but having worked for well over 30 years in the repair of professional sound equipment, I've seen much otherwise serviceable gear reduced to scrap due to the misguided (and usually very liberal) application of WD40.

Ask yourself, or any of the people here who design and build electronics for a living this, would you be happy to let Joe Public spray WD40 into an item of equipment that you have a responsibility for?

OPMMV

It`s great on rusty nuts and spark plug leads tho.

Ron(UK)

Point well taken. Seen from that point of view, (and remembering all the vcrs I've seen saturated with WD-40 because it was making a "squealing" noise), I must admit you're correct. As one career tech to another, I'm sure you can see my point. I sometimes forget that the "advice" to a novice servicer can get waaaay out of hand. I stand corrected. But do you know of ANY chemical product that would behave similarly, I.e. penetrate to the carbon button & contacts, that wouldn't leave a residue? I would be leery to use any aggressive solvents.

P.S. The screen name is not a delusional representation of my infinite electronic abilities, I just thought it sounds catchy. (And maybe it's just a little, little, liiiitle bit true)

The best I have ever found is/was a product from Philips called Contact Cleaner 390CCS, tho it does leave an oily film. I`m told that this is no longer available. I`m down to my last can, so if anyone knows who stocks it I`d be obliged.

Our 'leftpodian' friends seem to swear by Caig products for switch and pot cleaning, tho I dont thnk they are easily available on this side of the pond. A little touch of neat isopropanol is probably safest.

Ron(UK)

only

At the risk of (re)starting a WD40 war: WD40 is a blend of waxes and solvents. It is very good at DISSOLVING numerous kinds of polymers...such as those used to make flexible keypads, sealing electrolytic capacitors, moulding complex mechanical parts, adhesives, etc. WD40 has been found to be capable of dissolving (literally) the resistor material used in SOME potentiometers (linear and rotary), glue used to hold complex switches in assembly, and the conductivity-enhancing black coating on some IR remocon PCBs. It takes only a fraction of a drop to do any of this.

Given enough time, residue (wax) from a WD40 coating will attract enough ambient dust to form conductive paths where the designer did not intend them to be, thus destroying components. WD40 is a good TEMPORARY solution for squeaking door hinges...temporary because WAX IS NOT A LUBRICANT. WD40 can do nothing positive for electronic equipment other than hasten its replacement. IAW: You don't recall re-serviceing anything because of WD40 because the next failure was probably so catestrophic that the item went to the dustbin as soon as the smoke cleared.

Don't misunderstand...I'm a WD40 enthusiast. I have a 1-gallon tin of the stuff under my work bench for use as a cleaner...because it is the best I've found for cutting heavy grease, adhesive tape residue, and rinsing crap out of tiny ball-bearings. Just don't ever think of it as a "contact cleaner" or "tuner cleaner." It isn't.

Well said that man, that should be part of the FAQ.

Ron(UK)

At the risk of firing another "shot" that will spark the next WD-40 war, I feel compelled to speak again on the subject. In hindsight, I can see that an amateur or novice technician might get carried away using '40. But to an experienced tech, it can be a good product. And your implication that the literally tens of thousands of products I have serviced "went up in smoke", I find somewhat offensive. I am a quality technician, I have extensive training, and I successfully serviced most types of consumer electronic equipment from digital camcorders to vacuum-tube ham radios. I did not specialize; I serviced literally anything that came across my bench. Of course, there were some units that I was unable to repair that another tech was. But the reverse was also true. In the last 10 years of my career, I was the tech they turned to when nobody else could or would service a unit.

I will try to bear in mind that any advise I pass along in the future may be used by an inexperienced tech, and I will temper my responses accordingly. But at the places I have worked, WD-40 was commonplace; a qualified tech knows about the residue attracting contaminates over time, that's why you clean up afterwards. And I have to ask: Doesn't ANY lubricant have the same effect?

Don't take it personally, this is usenet.

I don't think anyone was deliberately impugning your technical skill, and no doubt most of the products that you applied WD40 to carried on working for some considerable time after you released them back into the wild. You, as I would, probably applied tiny amount in just the right place (tho you did advise flushing keyswitch contacts with it) - Probably for some jobs it`s fine, mechanical contacts, valve pins etc. but the fact is, It`s not the right product, and there`s plenty of stuff available that is specifically designed for the purpose.

I`m sure most if not all manufacturers of equipment would be aghast at the thought of someone spraying WD40 into their gear, and the manufacturers of WD40 expressly advise against using it on electronics.

Ron(UK)

We used to use CRC 2-22 (once in a gallon bucket - true story). It was much more suited to such uses.

Just wondering-what happened to the original poster?

Probly high as a kite off WD40 fumes ;)

Ron(UK)

servisol and lubri-limp -proper contact cleaner (non residue). Surprised as a tech you never used switch cleaner?!!

Probably just lurking until this thread settles down.

The next thing I need to deal with is a $1200 piece of equipment with a few flaky buttons sitting in my workshop right now. No need to rush. I want to be sure it will still be a $1200 piece of equipment after I'm done with it.

until this thread settles down.

if you use proper switch cleaner spray from an electronics dealer, and use it sparingly and in the right places, there's no reason why it should cease to be.

-B.

This is quite a bold assumption. It could be that the switch is defective and cleaning will do nothing. We see this frequently. We try to clean them and they may improve or not. Some just need to be replaced.

Leonard

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