Hi all,

I have a switch which isn't making electrical contact. It consists of two
leaf springs. Dead simple. They're springy enough to push against each
other alright. And I've cleaned them with ethanol (didn't work) isopropyl
alcohol (didn't work) and Servisol switch cleaning lubricant (didn't work
either). I am at a complete loss here. Has anyone come across something
like this? I can confidently say I never have!

On Sun, 15 Sep 2024 16:44:47 -0000 (UTC), Nick Hayward
<nhayward8990@protonmail.com> wrote:

>Hi all,
>
>I have a switch which isn't making electrical contact. It consists of two
>leaf springs. Dead simple. They're springy enough to push against each
>other alright. And I've cleaned them with ethanol (didn't work) isopropyl
>alcohol (didn't work) and Servisol switch cleaning lubricant (didn't work
>either). I am at a complete loss here. Has anyone come across something
>like this? I can confidently say I never have!

Suggest you look for bad contact in nearby detail.

RL

On Sun, 15 Sep 2024 13:08:10 -0400, legg wrote:

> On Sun, 15 Sep 2024 16:44:47 -0000 (UTC), Nick Hayward
> <nhayward8990@protonmail.com> wrote:
>
>>Hi all,
>>
>>I have a switch which isn't making electrical contact. It consists of
>>two leaf springs. Dead simple. They're springy enough to push against
>>each other alright. And I've cleaned them with ethanol (didn't work)
>>isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
>>(didn't work either). I am at a complete loss here. Has anyone come
>>across something like this? I can confidently say I never have!
>
> Suggest you look for bad contact in nearby detail.
>
> RL

You mean there may be nothing wrong with the switch itself?

Nick Hayward <nhayward8990@protonmail.com> wrote:

> Hi all,
>
> I have a switch which isn't making electrical contact. It consists of two
> leaf springs. Dead simple. They're springy enough to push against each
> other alright. And I've cleaned them with ethanol (didn't work) isopropyl
> alcohol (didn't work) and Servisol switch cleaning lubricant (didn't work
> either). I am at a complete loss here. Has anyone come across something
> like this? I can confidently say I never have!

I have had this happen when Hypoy gear oil has got on the contacts, but
as other have said, the fault may be elsewhere. Were you making your
measurements directly on the springs or on something attached to them?

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On 15 Sep 2024 at 21:44:07 BST, "Liz Tuddenham" <Liz Tuddenham> wrote:

> Nick Hayward <nhayward8990@protonmail.com> wrote:
>
>> Hi all,
>>
>> I have a switch which isn't making electrical contact. It consists of two
>> leaf springs. Dead simple. They're springy enough to push against each
>> other alright. And I've cleaned them with ethanol (didn't work) isopropyl
>> alcohol (didn't work) and Servisol switch cleaning lubricant (didn't work
>> either). I am at a complete loss here. Has anyone come across something
>> like this? I can confidently say I never have!
>
> I have had this happen when Hypoy gear oil has got on the contacts, but
> as other have said, the fault may be elsewhere. Were you making your
> measurements directly on the springs or on something attached to them?

A possibly short term solution is to rub very fine folded over emery paper
between the contacts. It tends to destroy plated contacts but might just get
the switch working.

--
Roger Hayter

On Sun, 15 Sep 2024 21:44:07 +0100, Liz Tuddenham wrote:

> Nick Hayward <nhayward8990@protonmail.com> wrote:
>
>> Hi all,
>>
>> I have a switch which isn't making electrical contact. It consists of
>> two leaf springs. Dead simple. They're springy enough to push against
>> each other alright. And I've cleaned them with ethanol (didn't work)
>> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
>> (didn't work either). I am at a complete loss here. Has anyone come
>> across something like this? I can confidently say I never have!
>
> I have had this happen when Hypoy gear oil has got on the contacts, but
> as other have said, the fault may be elsewhere. Were you making your
> measurements directly on the springs or on something attached to them?

No, I got the probes directly on the leaves themselves.

On 15 Sep 2024 21:03:04 GMT, Roger Hayter wrote:

> On 15 Sep 2024 at 21:44:07 BST, "Liz Tuddenham" <Liz Tuddenham> wrote:
>
>> Nick Hayward <nhayward8990@protonmail.com> wrote:
>>
>>> Hi all,
>>>
>>> I have a switch which isn't making electrical contact. It consists of
>>> two leaf springs. Dead simple. They're springy enough to push against
>>> each other alright. And I've cleaned them with ethanol (didn't work)
>>> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
>>> (didn't work either). I am at a complete loss here. Has anyone come
>>> across something like this? I can confidently say I never have!
>>
>> I have had this happen when Hypoy gear oil has got on the contacts, but
>> as other have said, the fault may be elsewhere. Were you making your
>> measurements directly on the springs or on something attached to them?
>
> A possibly short term solution is to rub very fine folded over emery
> paper between the contacts. It tends to destroy plated contacts but
> might just get the switch working.

Which is what I plan to do next, in fact. I have some 3000 grit paper
which should be close to perfect for this kind of thing. In fact I have a
full range from 3000 right through to 40. I'm hoping it won't require
anything below 1200, though!

On 2024-09-15 9:44 a.m., Nick Hayward wrote:
> Hi all,
>
> I have a switch which isn't making electrical contact. It consists of two
> leaf springs. Dead simple. They're springy enough to push against each
> other alright. And I've cleaned them with ethanol (didn't work) isopropyl
> alcohol (didn't work) and Servisol switch cleaning lubricant (didn't work
> either). I am at a complete loss here. Has anyone come across something
> like this? I can confidently say I never have!

Have you verified that the meter leads are making good electrical
contact to the switch blades? Oxidation can fool any of us! Touch one
probe to the switch blade, and touch the other probe further down the
blade - repeat on the other side, only then check for electrical contact
closure once you are certain you have good probe connections.

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
#7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

Cursitor Doom <cd999666@notformail.com> wrote:

> On Sun, 15 Sep 2024 21:44:07 +0100, Liz Tuddenham wrote:
>
> > Nick Hayward <nhayward8990@protonmail.com> wrote:
> >
> >> Hi all,
> >>
> >> I have a switch which isn't making electrical contact. It consists of
> >> two leaf springs. Dead simple. They're springy enough to push against
> >> each other alright. And I've cleaned them with ethanol (didn't work)
> >> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
> >> (didn't work either). I am at a complete loss here. Has anyone come
> >> across something like this? I can confidently say I never have!
> >
> > I have had this happen when Hypoy gear oil has got on the contacts, but
> > as other have said, the fault may be elsewhere. Were you making your
> > measurements directly on the springs or on something attached to them?
>
> No, I got the probes directly on the leaves themselves.

For the future, it is best to arrange the contacts so the gap between
them is vertical; that way any dirt falls out of them instead of being
ground into the surface. GPO telephone exchange equipment always had
the relays aligned that way.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On Sun, 15 Sep 2024 23:42:48 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:

>On Sun, 15 Sep 2024 21:44:07 +0100, Liz Tuddenham wrote:
>
>> Nick Hayward <nhayward8990@protonmail.com> wrote:
>>
>>> Hi all,
>>>
>>> I have a switch which isn't making electrical contact. It consists of
>>> two leaf springs. Dead simple. They're springy enough to push against
>>> each other alright. And I've cleaned them with ethanol (didn't work)
>>> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
>>> (didn't work either). I am at a complete loss here. Has anyone come
>>> across something like this? I can confidently say I never have!
>>
>> I have had this happen when Hypoy gear oil has got on the contacts, but
>> as other have said, the fault may be elsewhere. Were you making your
>> measurements directly on the springs or on something attached to them?
>
>No, I got the probes directly on the leaves themselves.

Soak some unbleached kraft paper in alcohol or kerosene, and
force between the leaves' contacting surfaces.
Move vigorously in a circular patternm, then remove and retest.

Nick Hayward = Cursitor Doom ?
Wouldn't have bothered, if I'd known.

RL

On Sun, 15 Sep 2024 22:46:18 -0700, John Robertson wrote:

> On 2024-09-15 9:44 a.m., Nick Hayward wrote:
>> Hi all,
>>
>> I have a switch which isn't making electrical contact. It consists of
>> two leaf springs. Dead simple. They're springy enough to push against
>> each other alright. And I've cleaned them with ethanol (didn't work)
>> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
>> (didn't work either). I am at a complete loss here. Has anyone come
>> across something like this? I can confidently say I never have!
>
> Have you verified that the meter leads are making good electrical
> contact to the switch blades? Oxidation can fool any of us! Touch one
> probe to the switch blade, and touch the other probe further down the
> blade - repeat on the other side, only then check for electrical contact
> closure once you are certain you have good probe connections.
>
> John :-#)#

Acting on the advice of someone very much more experienced with this
attenuator than I am, it's the case that the offending material was
silicon oxide. Something to do with contact sparking and silicon grease
that they used in the early versions of this device. The only remedy is
fine abrasive paper. I used 1500 grit in then end; very lightly just a few
strokes. it's fine again now - and before anyone says anything, there was
no gold plating on these contacts to rub off!

On Mon, 16 Sep 2024 10:24:59 -0400, legg wrote:

> On Sun, 15 Sep 2024 23:42:48 -0000 (UTC), Cursitor Doom
> <cd999666@notformail.com> wrote:
>
>>On Sun, 15 Sep 2024 21:44:07 +0100, Liz Tuddenham wrote:
>>
>>> Nick Hayward <nhayward8990@protonmail.com> wrote:
>>>
>>>> Hi all,
>>>>
>>>> I have a switch which isn't making electrical contact. It consists of
>>>> two leaf springs. Dead simple. They're springy enough to push against
>>>> each other alright. And I've cleaned them with ethanol (didn't work)
>>>> isopropyl alcohol (didn't work) and Servisol switch cleaning
>>>> lubricant (didn't work either). I am at a complete loss here. Has
>>>> anyone come across something like this? I can confidently say I never
>>>> have!
>>>
>>> I have had this happen when Hypoy gear oil has got on the contacts,
>>> but as other have said, the fault may be elsewhere. Were you making
>>> your measurements directly on the springs or on something attached to
>>> them?
>>
>>No, I got the probes directly on the leaves themselves.
>
> Soak some unbleached kraft paper in alcohol or kerosene, and force
> between the leaves' contacting surfaces.
> Move vigorously in a circular patternm, then remove and retest.
>
> Nick Hayward = Cursitor Doom ?
> Wouldn't have bothered, if I'd known.
>
> RL

Yeah, that's my name; don't wear it out!

Cursitor Doom <cd999666@notformail.com> wrote:

> On Sun, 15 Sep 2024 22:46:18 -0700, John Robertson wrote:
>
> > On 2024-09-15 9:44 a.m., Nick Hayward wrote:
> >> Hi all,
> >>
> >> I have a switch which isn't making electrical contact. It consists of
> >> two leaf springs. Dead simple. They're springy enough to push against
> >> each other alright. And I've cleaned them with ethanol (didn't work)
> >> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
> >> (didn't work either). I am at a complete loss here. Has anyone come
> >> across something like this? I can confidently say I never have!
> >
> > Have you verified that the meter leads are making good electrical
> > contact to the switch blades? Oxidation can fool any of us! Touch one
> > probe to the switch blade, and touch the other probe further down the
> > blade - repeat on the other side, only then check for electrical contact
> > closure once you are certain you have good probe connections.
> >
> > John :-#)#
>
> Acting on the advice of someone very much more experienced with this
> attenuator than I am, it's the case that the offending material was
> silicon oxide. Something to do with contact sparking and silicon grease
> that they used in the early versions of this device. The only remedy is
> fine abrasive paper. I used 1500 grit in then end; very lightly just a few
> strokes. it's fine again now - and before anyone says anything, there was
> no gold plating on these contacts to rub off!

That's worth remembering. I had always assumed silicone grease was
fairly benign and could be used anywhere, now I know differently.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On 17 Sep 2024 at 23:11:18 BST, "Cursitor Doom" <cd999666@notformail.com>
wrote:

> On Sun, 15 Sep 2024 22:46:18 -0700, John Robertson wrote:
>
>> On 2024-09-15 9:44 a.m., Nick Hayward wrote:
>>> Hi all,
>>>
>>> I have a switch which isn't making electrical contact. It consists of
>>> two leaf springs. Dead simple. They're springy enough to push against
>>> each other alright. And I've cleaned them with ethanol (didn't work)
>>> isopropyl alcohol (didn't work) and Servisol switch cleaning lubricant
>>> (didn't work either). I am at a complete loss here. Has anyone come
>>> across something like this? I can confidently say I never have!
>>
>> Have you verified that the meter leads are making good electrical
>> contact to the switch blades? Oxidation can fool any of us! Touch one
>> probe to the switch blade, and touch the other probe further down the
>> blade - repeat on the other side, only then check for electrical contact
>> closure once you are certain you have good probe connections.
>>
>> John :-#)#
>
> Acting on the advice of someone very much more experienced with this
> attenuator than I am, it's the case that the offending material was
> silicon oxide. Something to do with contact sparking and silicon grease
> that they used in the early versions of this device. The only remedy is
> fine abrasive paper. I used 1500 grit in then end; very lightly just a few
> strokes. it's fine again now - and before anyone says anything, there was
> no gold plating on these contacts to rub off!

Not to criticise your decision (which I actually suggested) there are lots of
other contact plating materials than gold. Some of them are thicker or softer
than others. Apart from other noble metals, nickel and tin spring to mind.

--

Roger Hayter