Fixing flaky buttons

[Hamad bin Turki al Salami]

I have a bunch of aging instruments I need to tune up. One common
problem with these things is the buttons become flaky over time.
(I'm not sure what the name for this kind of button is, but what
I'm talking about is a "stateless" push button, which functions
like a computer keyboard key. It is typically used to increment
a number or move a cursor or something. You push it and it moves
the cursor one space. You push it again to get another space.
Often, if you hold it down, a repeat kicks in after a delay of
a half second or so.)

Over time, the contacts inside the button become dirty or oxidized
or whatever and the button becomes flaky. You have to push hard
to get a response, or you get multiple responses from one push,
etc.

If I can get the button open, I can usually improve it by cleaning
it with alcohol, but sometimes even that doesn't completely fix
the problem.

Does anyone here have tips for this kind of thing?

I'd especially like to know if there are tricks for fixing these
without opening the buttons up. There are a lot of different
kinds of buttons and some are hard to open and some take me
a while to figure out how to open.

 

[StellarTech]

I have a bunch of aging instruments I need to tune up. One common
problem with these things is the buttons become flaky over time.
(I'm not sure what the name for this kind of button is, but what
I'm talking about is a "stateless" push button, which functions
like a computer keyboard key. It is typically used to increment
a number or move a cursor or something. You push it and it moves
the cursor one space. You push it again to get another space.
Often, if you hold it down, a repeat kicks in after a delay of
a half second or so.)

Over time, the contacts inside the button become dirty or oxidized
or whatever and the button becomes flaky. You have to push hard
to get a response, or you get multiple responses from one push,
etc.

If I can get the button open, I can usually improve it by cleaning
it with alcohol, but sometimes even that doesn't completely fix
the problem.

Does anyone here have tips for this kind of thing?

I'd especially like to know if there are tricks for fixing these
without opening the buttons up. There are a lot of different
kinds of buttons and some are hard to open and some take me
a while to figure out how to open.

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.

 

[Ron(UK)]

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)

 

[StellarTech]

I assume you are referring to pcb-mounted momentary contact switches. The

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.

 

[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)

 

[StellarTech]

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.

 

[StellarTech]

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)

 

[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.

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)

 

[webpa]

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.

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.

 

[Ron(UK)]

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)

 

[StellarTech]

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?

 

[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.

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)

 

[Homer J Simpson]

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.

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

http://www.crcindustries.com/crcwebmain/ but it may be discontinued now in
favor of other products.


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[StellarTech]

Just wondering-what happened to the original poster?

 

[Ron(UK)]

Just wondering-what happened to the original poster?

Probly high as a kite off WD40 fumes

Ron(UK)

 

[StellarTech]

Probly high as a kite off WD40 fumes

Ron(UK)

Oh, that was good! I had to come back three times before I could stop
laughing enough to focus on the keys...

 

[b]

". 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

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

 

[Hamad bin Turki al Salami]

Just wondering-what happened to the original poster?

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.

 

[b]

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.

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.

 

[Leonard Caillouet]

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