Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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One of the books I picked up on faultfinding and troubleshooting whilst
in London the other day (title escapes me but I can find it if anyone
cares) states that:

a) A bipolar transitor may be permanently damaged by dropping it on a
concrete floor from a height of over 4'. (I'm paraphrasing but that's the
gist of it).

Elsewhere it states that:

b) static sensitive components can be damaged by careless use of air
dusters, which can build up a static charge, in their vicinity.

Whilst I'm prepared to place some faith in assertion b) I'm reluctant to
do so in the case of a). However, I'm more concerned with b) because I
recently purchased a fair sized air compressor for blowing dust out of
the insides of test equipment which is of course considerably more
powerful than the aerosol cans the author was thinking about when he
asserted b).
Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?
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On Tuesday, 13 June 2017 21:24:50 UTC+1, Cursitor Doom wrote:
One of the books I picked up on faultfinding and troubleshooting whilst
in London the other day (title escapes me but I can find it if anyone
cares) states that:

a) A bipolar transitor may be permanently damaged by dropping it on a
concrete floor from a height of over 4'. (I'm paraphrasing but that's the
gist of it).

Elsewhere it states that:

b) static sensitive components can be damaged by careless use of air
dusters, which can build up a static charge, in their vicinity.

Whilst I'm prepared to place some faith in assertion b) I'm reluctant to
do so in the case of a). However, I'm more concerned with b) because I
recently purchased a fair sized air compressor for blowing dust out of
the insides of test equipment which is of course considerably more
powerful than the aerosol cans the author was thinking about when he
asserted b).
Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?


I'd first be mindful of mechanical damage from doing that.
When was the book written? Germanium?


NT
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On 14/06/2017 6:21 AM, Cursitor Doom wrote:
One of the books I picked up on faultfinding and troubleshooting whilst
in London the other day (title escapes me but I can find it if anyone
cares) states that:

a) A bipolar transitor may be permanently damaged by dropping it on a
concrete floor from a height of over 4'. (I'm paraphrasing but that's the
gist of it).

Elsewhere it states that:

b) static sensitive components can be damaged by careless use of air
dusters, which can build up a static charge, in their vicinity.

Whilst I'm prepared to place some faith in assertion b) I'm reluctant to
do so in the case of a). However, I'm more concerned with b) because I
recently purchased a fair sized air compressor for blowing dust out of
the insides of test equipment which is of course considerably more
powerful than the aerosol cans the author was thinking about when he
asserted b).
Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?


**a) is possible (barely). Rip the top off a TO3 transistor and examine
the construction. You'll get the idea. As for b), I have no idea why any
sane person would use compressed air on any product, unless required by
very specific circumstances. It is a daft idea. A soft brush and a
vacuum cleaner is a far superior and gentler way to do things. Even
better, there is far less chance that the dust will end up inside pots,
switches and other mechanical components.

--
Trevor Wilson
www.rageaudio.com.au
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On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!

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Cursitor Doom wrote:

One of the books I picked up on faultfinding and troubleshooting whilst
in London the other day (title escapes me but I can find it if anyone
cares) states that:

a) A bipolar transitor may be permanently damaged by dropping it on a
concrete floor from a height of over 4'. (I'm paraphrasing but that's the
gist of it).

Elsewhere it states that:

b) static sensitive components can be damaged by careless use of air
dusters, which can build up a static charge, in their vicinity.

Whilst I'm prepared to place some faith in assertion b) I'm reluctant to
do so in the case of a). However, I'm more concerned with b) because I
recently purchased a fair sized air compressor for blowing dust out of
the insides of test equipment which is of course considerably more
powerful than the aerosol cans the author was thinking about when he
asserted b).
Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?


The original, point-contact trasnsistors from the 1950's were quite fragile
devices, basically a pair of etched hair whiskers on a Germanium speck.

Supposedly, it is the tiny dust particles in an air stream that create the
triboelectric charge. So, clean air should be better. I live in Missouri,
so we have enough humidity that ESD is a fairly rare phenomenon. I have
used vacuum cleaners to clean old computer gear, and never had damage,
although I was concerned about the possibility.

I have seen a fat spark produced when firing off a CO2 fire extinguisher,
which seemed like a pretty big design defect. They should have made the
hose and nozzle with a static dissipative material.

Jon


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On Tuesday, 13 June 2017 22:03:32 UTC+1, Cursitor Doom wrote:
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


I think those would be some of the more fragile items. Many have an extremely thin filament stretching a few mm with no support at all.


NT
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On Wed, 14 Jun 2017 06:50:59 +1000, Trevor Wilson wrote:

I have no idea why any
sane person would use compressed air on any product, unless required by
very specific circumstances. It is a daft idea.


I beg to differ. Air compressors totally *rock*! Having used one now for
7 years I could not imagine going back to *any* other method. Nothing
else comes close.
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On Tue, 13 Jun 2017 16:16:01 -0500, Jon Elson wrote:

so we have enough humidity that ESD is a fairly rare phenomenon. I have
used vacuum cleaners to clean old computer gear, and never had damage,
although I was concerned about the possibility.


I'd be more worried about the action of brushing itself giving rise to
static charges. It's hard to know for sure what

I have seen a fat spark produced when firing off a CO2 fire
extinguisher, which seemed like a pretty big design defect.


Yes, been there; done that. In fact a gave a co-worker a pretty nasty
shock by using a CO2 extinguisher which must have charged me up to 10s of
thousands of volts whilst I put out a fire with it. It was a very noisy
situation so I needed to shout into his ear to make myself heard and this
terrific blue spark shot straight from my nose to his ear! Had no effect
on me but sent him reeling. You should have seen the look on his face! :-

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On 14/06/2017 7:39 AM, Chris wrote:
On Wed, 14 Jun 2017 06:50:59 +1000, Trevor Wilson wrote:

I have no idea why any
sane person would use compressed air on any product, unless required by
very specific circumstances. It is a daft idea.


I beg to differ. Air compressors totally *rock*! Having used one now for
7 years I could not imagine going back to *any* other method. Nothing
else comes close.


**OK. I'll trade your 7 years with my 40 years professionally servicing
electronic equipment. And yes, I have a (filtered) air line into my
workshop. However, a vac is vastly more preferable and much safer. I do
use air, very sparingly, when required.

--
Trevor Wilson
www.rageaudio.com.au
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On Tuesday, June 13, 2017 at 2:03:32 PM UTC-7, Cursitor Doom wrote:
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


Oh, no; a point contact diode can easily jar out of spec. There was even
an old device (the 'coherer') which reformed a rectifying contact by
motorized shaking during normal operation.


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On Wed, 14 Jun 2017 08:49:40 +1000, Trevor Wilson wrote:

**OK. I'll trade your 7 years with my 40 years professionally servicing
electronic equipment. And yes, I have a (filtered) air line into my
workshop. However, a vac is vastly more preferable and much safer. I do
use air, very sparingly, when required.


Yeah, air is so expensive you gotta use it sparingly hehehe!
The one caveat I would add about blasting boards with (clean) compressed
air is that you *gotta* do it outdoors for all sorts of reasons I can't
be assed to go into here.

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On 14/06/2017 9:02 AM, Chris wrote:
On Wed, 14 Jun 2017 08:49:40 +1000, Trevor Wilson wrote:

**OK. I'll trade your 7 years with my 40 years professionally servicing
electronic equipment. And yes, I have a (filtered) air line into my
workshop. However, a vac is vastly more preferable and much safer. I do
use air, very sparingly, when required.


Yeah, air is so expensive you gotta use it sparingly hehehe!


**Read what I wrote, moron. Using air spreads dust to places inside the
equipment where you don't want it to go. Like pots and switches for
instance. How do you prevent that from occurring?

The one caveat I would add about blasting boards with (clean) compressed
air is that you *gotta* do it outdoors for all sorts of reasons I can't
be assed to go into here.


**And yet another good reason to use a vac.


--
Trevor Wilson
www.rageaudio.com.au
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In article ,
Jon Elson wrote:

I have seen a fat spark produced when firing off a CO2 fire extinguisher,
which seemed like a pretty big design defect.


You're certainly right - if you had used it around any sort of
flammable vapors, the spark might have started a fire. ;-)

They should have made the
hose and nozzle with a static dissipative material.


I'm not sure that would have helped. Where would the charge have
gone, during the second or three that one was blasting away with CO2?
There'd be only a very limited amount of charge flow back into the CO2
cloud (neither the CO2 nor the ice crystals which were
triboelectrically active, will be particularly conductive), or
dissipate into the air nearby. The major charge-sink would still be
the body of the person wielding the extinguisher.

http://www.ece.rochester.edu/~jones/demos/charging.html is
interesting. Apparently, even aluminum can generate a charge via
triboelectric effect, and it's about as static-conductive as you could
ask for.





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In article ,
Trevor Wilson wrote:

The one caveat I would add about blasting boards with (clean) compressed
air is that you *gotta* do it outdoors for all sorts of reasons I can't
be assed to go into here.


**And yet another good reason to use a vac.


In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.

A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).



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On 14/06/2017 9:43 AM, Dave Platt wrote:
In article ,
Trevor Wilson wrote:

The one caveat I would add about blasting boards with (clean) compressed
air is that you *gotta* do it outdoors for all sorts of reasons I can't
be assed to go into here.


**And yet another good reason to use a vac.


In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.


**I confess that I had not thought of that, but certainly, spreading any
dust around can be injurious to many people.


A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).


**Of course. And MUCH safer for the equipment.


--
Trevor Wilson
www.rageaudio.com.au


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On 6/13/2017 5:02 PM, Trevor Wilson wrote:
On 14/06/2017 9:43 AM, Dave Platt wrote:
In article ,
Trevor Wilson wrote:

The one caveat I would add about blasting boards with (clean)
compressed
air is that you *gotta* do it outdoors for all sorts of reasons I can't
be assed to go into here.

**And yet another good reason to use a vac.


In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.


**I confess that I had not thought of that, but certainly, spreading any
dust around can be injurious to many people.


A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).


**Of course. And MUCH safer for the equipment.


How do you get the cat hair out of the CPU heat sink underneath the fan?
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On Tue, 13 Jun 2017 16:43:38 -0700, (Dave
Platt) wrote:

In article ,
Trevor Wilson wrote:

The one caveat I would add about blasting boards with (clean) compressed
air is that you *gotta* do it outdoors for all sorts of reasons I can't
be assed to go into here.


**And yet another good reason to use a vac.


In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.

A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).


I have not had rodents in my equipment, but every few years I completely
disassemble my desktop computer. I do it outdoors on very hot sunny
summer days. I first remove all drives and set them aside. Then I unplug
all the boards, and blast each board with water using the garden hose. I
do the same with the motherboard, and I open the power supply and blast
that with water (that's where most of the dirt is). Then I leave all of
it sit in the hot sun all day long to completely dry.

The drives should not get soaked. Those I dust off with a fine dry scrub
brush, and wipe the outer case with a damp rag.

I always take the CPU and CPU cooler off the motherboard too, so water
dont stay below it. (I apply new heat transfer grease to the CPU when I
reassemble).

Than I reassemble the whole computer. It always works fine. The computer
I am using right now has had this done to it several times now.

The key is making 100% sure all water is gone before using it.

Anyhow, if rodents were in some equipment, I'd surely wash everything
with a strong blast of water. But I would not soak switches and pots. If
a little water gets in, that should be ok, but dont "flood" them.

I should mention that this began when I acquired several computers that
were in a flood. The drives were trash, ALL OF THEM, including Hard
Drives, FLoppy Drives and CD Drives. The boards were covered with mud. I
opened them, hosed them very well, and after drying, I reassembled. They
all worked fine, but I had to replace the drives.

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On Tue, 13 Jun 2017 20:59:53 -0000 (UTC), Cursitor Doom
wrote:

On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


Dont try that with a vaccuum tube!

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On Wed, 14 Jun 2017 06:50:59 +1000, Trevor Wilson
wrote:

I have no idea why any
sane person would use compressed air on any product, unless required by
very specific circumstances. It is a daft idea. A soft brush and a
vacuum cleaner is a far superior and gentler way to do things. Even
better, there is far less chance that the dust will end up inside pots,
switches and other mechanical components.


I have an air compressor at home, in my palatial office, and a small
one in my car. It was one of the best purchases I ever made. Lots of
benefits:

1. It totally eliminated black nose disease, where the dust found
inside computahs, test equipment, and flea market junk does not end up
being inhaled and producing a disgusting black goo when ejected by
sneezing.

2. I blow out EVERYTHING that arrives in the office that has even the
possibility of containing dust. The result is that I only have to
vacuum the office perhaps every 2 months.

3. I don't worry much about static electricity, but I do watch the
relative humidity. If it drops below about 20%, I start throwing
lighting bolts of static electricity. At that point, I take
precautions, like discharging myself, wearing anti-static shoe
coverings, and generally avoiding anything risky. So far, I've only
blown up a few things in 30+ years, none of which involved an air
compressor.

4. I have an electrostatic voltmeter for measuring static buildup.
Something like these but home made:
https://www.google.com/search?tbm=isch&q=electrostatic+voltmeter
I don't guess, I measure.

5. I frequently wash PCB's and equipment. Getting them dry takes
some time. So, I speed things up by blowing the water out from under
components and in inaccessible locations. Without compressed air, a
keyboard wash takes about a week to dry completely. With compressed
air, 24 hrs will usually do the trick.

However, there are disadvantages:

1. Everyone in the building asks me to put air in their tires,
especially the bicycle riders. I have 100ft of air hose so that I
don't need to drag the compressor outside.

2. An air compressor and air tools are noisy but I'm good at ignoring
complaints from the neighbors.

3. I have to remember to drain the condensed water out of the tank or
I end up spraying rusty water on everything. I could get a
filter/dryer, but don't want to spend my life cleaning them.

Incidentally, I've convinced some friends and competitors to buy air
compressors for their office or shop. All have been very successful.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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On 14/06/2017 11:58 AM, mike wrote:
On 6/13/2017 5:02 PM, Trevor Wilson wrote:
On 14/06/2017 9:43 AM, Dave Platt wrote:
In article ,
Trevor Wilson wrote:

The one caveat I would add about blasting boards with (clean)
compressed
air is that you *gotta* do it outdoors for all sorts of reasons I
can't
be assed to go into here.

**And yet another good reason to use a vac.

In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.


**I confess that I had not thought of that, but certainly, spreading any
dust around can be injurious to many people.


A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).


**Of course. And MUCH safer for the equipment.


How do you get the cat hair out of the CPU heat sink underneath the fan?


**I vacuum it out, possibly with the aid of a brush.

--
Trevor Wilson
www.rageaudio.com.au


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On Tue, 13 Jun 2017 20:21:10 -0000 (UTC), Cursitor Doom
wrote:

Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?


I worked in a factory once that did a lot of cleaning of electronic
modules. Air was supplied by a central compressor. I never had a
problem with static and I don't think anyone else did but how would we
have known as many of the modules were already faulty.

Steve

--
Neural Network Software for Windows http://www.npsnn.com

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On 13/06/2017 21:21, Cursitor Doom wrote:
One of the books I picked up on faultfinding and troubleshooting whilst
in London the other day (title escapes me but I can find it if anyone
cares) states that:

a) A bipolar transitor may be permanently damaged by dropping it on a
concrete floor from a height of over 4'. (I'm paraphrasing but that's the
gist of it).

Elsewhere it states that:

b) static sensitive components can be damaged by careless use of air
dusters, which can build up a static charge, in their vicinity.

Whilst I'm prepared to place some faith in assertion b) I'm reluctant to
do so in the case of a). However, I'm more concerned with b) because I
recently purchased a fair sized air compressor for blowing dust out of
the insides of test equipment which is of course considerably more
powerful than the aerosol cans the author was thinking about when he
asserted b).
Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?


I've used a 1KW handheld Martindale blower for decades, no known static
problem ,just occassional physical breakage of shielding or something
like that, because of the air pressure involved, blowing out
tarry/greasy/hairy crud.
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"Cursitor Doom" wrote in message
news
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


diodes would be OK but die mounting and bond wires in some germanium
transistors was well, err - a bit amateurish.

Nowadays; suppliers pack *ANY* components in anti-static bags - it used to
be some sort of clue which bits to handle with care.

There's some unexpected parts on the vulnerable list, so maybe they have a
point.

molded semiconductors can be subjected to pretty much anything that doesn't
break the case.

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wrote in message
...
On Tuesday, 13 June 2017 22:03:32 UTC+1, Cursitor Doom wrote:
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


I think those would be some of the more fragile items. Many have an
extremely thin filament stretching a few mm with no support at all.


The first successful anti aircraft shell proximity fuze that could be fired
out of a gun had 3 hearing aid style tubes.

The thyratron obviously isn't a hearing aid tube - its about the sixe &
shape of the glass envelope.



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"whit3rd" wrote in message
...
On Tuesday, June 13, 2017 at 2:03:32 PM UTC-7, Cursitor Doom wrote:
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


Oh, no; a point contact diode can easily jar out of spec. There was even
an old device (the 'coherer') which reformed a rectifying contact by
motorized shaking during normal operation.


AFAIK: the point is "burned in" during manufacture. The weld is pretty much
the alloying process that creates the PN junction.

They're much less fragile than the old catswhisker/galena crystal.

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wrote in message
...
On Tue, 13 Jun 2017 20:59:53 -0000 (UTC), Cursitor Doom
wrote:

On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


Dont try that with a vaccuum tube!


I've seen one or two bounce - not very often though.

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"mike" wrote in message
news
On 6/13/2017 5:02 PM, Trevor Wilson wrote:
On 14/06/2017 9:43 AM, Dave Platt wrote:
In article ,
Trevor Wilson wrote:

The one caveat I would add about blasting boards with (clean)
compressed
air is that you *gotta* do it outdoors for all sorts of reasons I
can't
be assed to go into here.

**And yet another good reason to use a vac.

In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.


**I confess that I had not thought of that, but certainly, spreading any
dust around can be injurious to many people.


A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).


**Of course. And MUCH safer for the equipment.


How do you get the cat hair out of the CPU heat sink underneath the fan?


Its very easy when you don't have a cat - but since you do, odour killing
cat litter is great for packing in gear that came from a heavy smoker
household.

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"Trevor Wilson" wrote in message
...
On 14/06/2017 11:58 AM, mike wrote:
On 6/13/2017 5:02 PM, Trevor Wilson wrote:
On 14/06/2017 9:43 AM, Dave Platt wrote:
In article ,
Trevor Wilson wrote:

The one caveat I would add about blasting boards with (clean)
compressed
air is that you *gotta* do it outdoors for all sorts of reasons I
can't
be assed to go into here.

**And yet another good reason to use a vac.

In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.

**I confess that I had not thought of that, but certainly, spreading any
dust around can be injurious to many people.


A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).

**Of course. And MUCH safer for the equipment.


How do you get the cat hair out of the CPU heat sink underneath the fan?


**I vacuum it out, possibly with the aid of a brush.


Since de fluxing solvents were banned to protect the ozone layer, most
electronics is cleaned with water - sometimes its an option, sometimes it
isn't.

Dish wash detergent works great, but they thicken it with salt - so make
sure you rinse it all out.

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"Dave Platt" wrote in message
...
In article ,
Jon Elson wrote:

I have seen a fat spark produced when firing off a CO2 fire extinguisher,
which seemed like a pretty big design defect.


The one I fished out of a skip is now fitted with a tyre adaptor and used
for blowing tubeless tyre onto the rim.

You have to hold it upside down - if the syphon tube puts liquid CO2 into
the tyre, the rim starts creaking ominously.

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"Stephen Wolstenholme" wrote in message
...
On Tue, 13 Jun 2017 20:21:10 -0000 (UTC), Cursitor Doom
wrote:

Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?


I worked in a factory once that did a lot of cleaning of electronic
modules. Air was supplied by a central compressor. I never had a
problem with static


At tea break a bunch of us sat on the compressor - somehow I always ended up
next to the intake filter, and I tend to fart.

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On Fri, 16 Jun 2017 21:48:37 +0100, Ian Field wrote:

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.


Are you the same Ian Field that has authored several books on UHF/VHF
subjects?

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On Sunday, June 18, 2017 at 11:44:48 AM UTC-4, Cursitor Doom wrote:
On Fri, 16 Jun 2017 21:48:37 +0100, Ian Field wrote:

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.


Are you the same Ian Field that has authored several books on UHF/VHF
subjects?


Plasma physics too...

oh sorry that was Ion Fields. :^)

George H.
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On 2017/06/16 1:48 PM, Ian Field wrote:


"Cursitor Doom" wrote in message
news
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT


Haha! I think even those old germanium diodes would easily cope with a
four foot fall!


diodes would be OK but die mounting and bond wires in some germanium
transistors was well, err - a bit amateurish.

Nowadays; suppliers pack *ANY* components in anti-static bags - it used
to be some sort of clue which bits to handle with care.

There's some unexpected parts on the vulnerable list, so maybe they have
a point.

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.


IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

John ;-#)#



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compressed air can over-speed some small fans...

m

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On 6/19/2017 3:43 PM, John Robertson wrote:
IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

John ;-#)#


For the same reason drive through ATMs have instructions in Braille.

One kind of something is cheaper to inventory than two kinds of
something.

If you don't inventory non-static bags, nobody gets sensitive parts
in the wrong bags.


--
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http://www.foxsmercantile.com

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On 2017/06/19 2:07 PM, Foxs Mercantile wrote:
On 6/19/2017 3:43 PM, John Robertson wrote:
IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

John ;-#)#


For the same reason drive through ATMs have instructions in Braille.

One kind of something is cheaper to inventory than two kinds of
something.

If you don't inventory non-static bags, nobody gets sensitive parts
in the wrong bags.



Now that makes sense. I imagine that the cost of anti-static vs regular
bags is minuscule when you buy at Digi-Keys volume.

Thanks,

John :-#)#
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On 19.06.2017 22:43, John Robertson wrote:
On 2017/06/16 1:48 PM, Ian Field wrote:

Nowadays; suppliers pack *ANY* components in anti-static bags - it
used to be some sort of clue which bits to handle with care.

There's some unexpected parts on the vulnerable list, so maybe they
have a point.

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.


IC sockets though? Why do they pack them in anti-static bags
(Digi-Key)!


Most likely for compliance reasons. Thanks to the general CYA style
over-protectiveness, ESD safety rules are going postal. In various
places, rather than using common sense and somewhat educated employees,
they don't allow any sort of non-ESD-protected items on the production
floors any more. Having the sockets delivered in a non-dissipative
plastic bag would have some QC lunatics throw a hissy fit and run
screaming because they found something (the bag) that was (allegedly)
compromising the ESD safety of the factory

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On Mon, 19 Jun 2017 16:07:31 -0500, Foxs Mercantile
wrote:

For the same reason drive through ATMs have instructions in Braille.


Not really. Drive-up ATMs have Braille because it is not uncommon for
a blind person to take a cab or have a friend drive them to the bank
and use the ATM from the back seat or get out and walk to the drive-up
ATM while their friend monitors them for safety. The National
Federation of the Blind insisted that ALL ATMs provide a means for use
by blind people.
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