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push-push latching switch (wah-wah/effects pedal) renovation

From a wah-wah pedal only 2 years old so I don't see the point of replacing with more of the same, as these symptoms are very common. Poor bypass function and now total failure to switch between on and off Both 1.8mm x (11 down to 10mm swaged )stainless steel rivets ground off to separate the halves

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Unless anyone knows differently then I suspect the poor bypass contact is due to the interior packed with non-conductive grease. Carling, Mexico is the make of this one , single pole c/o, silver plated contacts and dumb-bell that can just about be seen in the centre of the top image,then a locating cup, then compression spring, then brass cup that seats the end of the swinging arm marked L in the next images. The dumbbell jumps the 2 contacts at the top of the image and runs along the continuous lower one. (not sufficient control over exposure on a basic camnera) Cleaned the silicone grease out and will replace with heavily graphited silicone grease,as not used for mains switching here, otherwise 1A 250V / 3A

125V rating. Why silver plating and then non-conductive grease in low current/ low voltage use ? There must be a "ball point pen" type latch action in the bush part so the down action pushes the L arm one way then the other on the next down stroke, with a click of its action on each upstroke. Presumably due to wear the underside of the button eventually bottoms against the end of the threaded part marked V, when L is only half way across. It needs to go a bit further than half for L to swing across, via the dumbell/cup spring sub-component action , to the other side. Slightly tightened a small Jubilee clip around the threaded bush, as a guide, and hacksawed off about 2mm at the V position, not apparent in these images, so can be quite neat.

No matter, in this case (not mains use), as will replace the rivets with Spanish windlass "E string" wire over 2 pins and glued in place. Anyone know of a source of such small diameter /long rivets for other occassions?

Of course just fixing the lack of switching does not require removing the rivets

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Reply to
N Cook
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plenty of spring in the ompression spring between dumbell and brass cup, so no lack of contact closure pressure , leading to the bypass problem

Reply to
N_Cook

just found this concerning Carling switches

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Featured Article :: A comparison of boost pedals :: by Ken Nossardi

Footswitches One of the first things to go out in a pedal, as many can attest to, is the footswitch - often, the weak link in the chain. This would appear to be worth some attention especially considering the prices some of these units command.

The SD, like many other pedals using the same Carling footswitches, had footswitch operation problems. Oddly enough, another Z Vex unit this user tested recently which used the same Carling switch, also had footswitch operation problems. One manufacturer stated that ever since Carling moved the production of their footswitches to Mexico (the Z Vex units had Carling Mexico-produced switches), it appeared the quality of their footswitch deteriorated. Geoffrey Teese of Real McCoy Custom wahs believes the move to Mexico was more coincidental and might have more to do with the Carling workforce knowing how to manipulate the proper manufacturing of a switch with the machinery used. When Teese was using the Carlings in his wahs (he is now currently using a switch from CIC), he reported that out of 10 wahs produced he would have 6 replaced before shipping and over time the other wahs with Carlings in them are being replaced one-by-one. Zachary Vex of Z Vex commented, "The tooling they use to make them is getting worn out. Many of us pedal-makers have complained, but it falls on deaf ears at Carlingswitch. They just don't care... They know they have the corner on the market and I've heard they refuse to improve the tooling, which is over 35 [40+] years old. I throw away about 10 per 100 as it is." Yet another pedal-maker commented, "Out of 1000 switches about 50 were dead right out of the box and another 50 failed after a short use. I sent them back and will never buy or recommend them again." This would appear to be a rather high failure rate for switches to encounter at the production stage not to mention failures that occur in the field thereafter. A rather disturbing thought and a frustrating experience when one is on stage in the middle of a performance and the footswitch decides to act up. Recently, this user auditioned a fuzz unit by an upcoming boutique pedal-maker that also used Carling footswitches with operation problems. After reporting the switch problem to the maker, he mentioned that out of 100 fuzz units produced this was the only reported problem. However, for reasons unrelated to reliability, this maker has changed footswitches to one used by many of the other pedal-makers.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Reply to
N_Cook

That's all very interesting, but if the switch really is crappily made in the first place, how is your pulling it to bits and 'remanufacturing' the defectively made internal parts, going to help ? FWIW, the Maplin switches are made by Alpha. I've used a few, and not had a problem with them. I have to say that the music shop that I get most of that sort of work from, doesn't send me a whole lot of pedals with failed switches. I need to speak to the owner today. I'll ask him if he has a lot of trouble with the ones he sells, and if so, is it soon enough in their life, for them to be returned to his supplier, under warranty.

Arfa

Reply to
Arfa Daily

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This particular one is Cry Baby GCB 95. The poor bypass is also a common problem according to someone known to the owner, a knowledgable source of such info. Ask him about poor bypass issues.

If there is non-conductive grease in other , otherwise 240V rated switches, then that could be a generic problem with all switch makes, used for low V, low A purposes.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Reply to
N_Cook

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If i'd not opened it up, no one would have been the wiser. I think I agree with the comment in the quote about machine tool wear. I've not removed the rivet that holds the ratchet mechanism - maybe shown on a patent site somewhere. I suspect that ratchet mechanism, produced by worn dies, is just enough to bring that swing lever over to just over half-way when tested off the production line. With, now, no reserve for in-use wear.

This foot pedal looks hardly used, even a thin plastic notice stiker on the rubber footpad is still in perfect condition and fully stuck down, just some slight image loss over the ribs of the rubber.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Reply to
N_Cook

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