Static is [not] your friend - vacuuming PC?

[Al Dykes]

The web page descriptions are indeed fairly funny, if you know
what they are talking about. But I highly suspect anyone with a
limited background in Electro Static Discharge will be more
confused than not.


Yep. Quite a lot.

*Moving* *dry* *air* around is a great way to build up a static
charge on any component that is an insulator.

Hence *compressed* *dry* *air* and *vacuum* *cleaners* are not
good ideas. In fact, compressed air might be worse because it
can forcefully blast dust into places it wouldn't otherwise go.

If you get enough charge (a few thousand volts, for example, is
common), it will then break down the insulation between the
charge and the next nearest object that is either also holding a
charge or is able to dissipate the charge (e.g., a conductor).
The current flow when that happens is what kills your computer.
And it isn't just that specific current, but also any current
induced into other conductors as a result of that current.

The way to get the dust out of a computer case safely is to use
a damp rag to manually pick up dust. It shouldn't be so wet
that it drips moisture (though that isn't necessarily bad
either, see below), but needs to be damp enough that dust will
stick to it and static cannot build up on it. I personally
prefer to have a large bowl of water mixed with a little
household cleaner (such as 409 or Mr. Clean), in which the dust
rag (a well worn bathroom wash cloth or a thin dish towel, is
nice) is washed as it get dirty. The soapy water in the bowl
should be changed somewhat regularly too, i.e. when it gets so
dirty that as much dirt moves from the water to the rag as from
the rag to the water!

Which type of soap to use does make a difference. The idea is
something that will dissolve any grease film or other coating
that might be present, but even more important is that it be a
good water dispersant. Automatic dishwater soap is perhaps the
best in that respect.

I've worked with professional disaster cleanup crews that use
deionized distilled water with a pressure washer, set at modest
pressure. Nothing added. Immediatly after the component is hosed off
they pop the item is a standard commercial convection oven set to
about 160F for a few minutes.

As a practical matter, I see no problem with cans of compressed gas.
Use a wrist strap if the equimpment is made of unreplacableium.

 

[Floyd L. Davidson]

[ lots of stuff we agree on snipped ]

As a practical matter, I see no problem with cans of compressed gas.
Use a wrist strap if the equimpment is made of unreplacableium.

There are two problems with cans of compressed gas. One is just
moving dry air around is, all by itself, a way to generate a
static charge.

The other is that any blast of air can force dirt particles into
places that they don't come out of. That isn't the worst thing
in the world, but it can occasionally have bad effects. There
aren't typically many things in a computer where it is likely to
do anything though. (The place that always annoyed me when
someone used compressed air was in any rack full of
"miscellaneous drop equipment" in a long distance telephone
office. Which is to say, a rack full of relays. Relays full of
dust particles become high maintenance items...)

 

[kony]

Staples and Office Depot have cans of air. Costco has them dirt cheap,
buy you need to buy a truckload.

One full size can will clean out several computers.

vacuums generate static charge. A discharge below the level of human
perception can damage semiconductors.

Officemax and Office Depot(?) used to have them FAR, I have
a drawer full that were free.

 

[Franc Zabkar]

*Moving* *dry* *air* around is a great way to build up a static
charge on any component that is an insulator.

Hence *compressed* *dry* *air* and *vacuum* *cleaners* are not
good ideas. In fact, compressed air might be worse because it
can forcefully blast dust into places it wouldn't otherwise go.

I don't have an opinion either way, but I offer the following two
observations.

(1) Fans blow air across the motherboard and at expensive components
all day long.

(2) Technicians use a heat gun (which blows very hot dry air) when
troubleshooting thermally sensitive components.

The way to get the dust out of a computer case safely is to use
a damp rag to manually pick up dust. It shouldn't be so wet
that it drips moisture (though that isn't necessarily bad
either, see below), but needs to be damp enough that dust will
stick to it and static cannot build up on it.

When cleaning dirty electronic appliances I brush the PCBs with
isopropyl alcohol, or methylated spirits if isopropyl is unavailable.
When cleaning the insides of TVs and other very dusty equipment I use
a vacuum cleaner because any other method just wouldn't be expedient,
IMO.


- Franc Zabkar

 

[Floyd L. Davidson]

I don't have an opinion either way, but I offer the following two
observations.

(1) Fans blow air across the motherboard and at expensive components
all day long.

There are several important differences though. The two most
important are that the air is not drier than the surrounding air
and that the volume and speed of air on any given component is
very small over a long period of time.

Compare that to either a vacuum or a compressed air source, and
the difference is great (as far as generating a static charge).

(2) Technicians use a heat gun (which blows very hot dry air) when
troubleshooting thermally sensitive components.

That is a relatively poor practice.

In both instances above though, note that the equipment is
powered up, which means that it is definitely grounded and
relatively able to disperse any charge build up.

When cleaning dirty electronic appliances I brush the PCBs with
isopropyl alcohol, or methylated spirits if isopropyl is unavailable.

That sounds like an *excellent* technique. "Tuner cleaner"
sprays are also good.

When cleaning the insides of TVs and other very dusty equipment I use
a vacuum cleaner because any other method just wouldn't be expedient,
IMO.

Not so good... but to be honest, it probably isn't all that bad
either, assuming you have pretty high humidity, which makes all
of these things very forgiving.

If you have very low humidity, or if you do this to a large number
of items, there will be a significant number of related failures.


Reminds me of a story I once heard, from back in the 70s about a
company manufacturing small precision film resistors. They were
experiencing extremely high return rates from out of spec parts.

As part of their probe into what was going on, they decided to
order a test shipment of similar devices from a Japanese
competitor. They ordered up "1000 ea Precision Resistors" and
specified that they would accept no more than 6 percent out of
tolerance. That was the spec they were failing to meet. Much
to their embarrassment, the Japanese folks didn't understand.

They received a box, with two bundles inside. The large one was
labeled "1000 each precision resistors". The smaller one had a
note on it which said something to the effect of "Here are your
6% out of tolerance items." ;-)

They obviously needed to try harder...

What they eventually found was their shipping department was
packaging these thin film resistors in paper envelopes, and the
ESD produced by inserting/removing them was sometimes zapping
the thin film enough to change the resistance. The problem was
fixed by using anti-static plastic packaging.

 

[James H. Fox]

Reminds me of a story I once heard, from back in the 70s about a
company manufacturing small precision film resistors. They were
experiencing extremely high return rates from out of spec parts.

As part of their probe into what was going on, they decided to
order a test shipment of similar devices from a Japanese
competitor. They ordered up "1000 ea Precision Resistors" and
specified that they would accept no more than 6 percent out of
tolerance. That was the spec they were failing to meet. Much
to their embarrassment, the Japanese folks didn't understand.

They received a box, with two bundles inside. The large one was
labeled "1000 each precision resistors". The smaller one had a
note on it which said something to the effect of "Here are your
6% out of tolerance items." ;-)

That is too funny. And it is probably true.

 

[Franklin]

Electrostatic discharge can produce some intersting effects
on semiconductors and the risk shouldn't be discounted.

However I have cleaned out the interior of countless cases
with no apparent ill effect- using a soft haired paintbrush
in one hand whilst hovering over the area with the nozzle of
a domestic vacuum cleaner in the other. Due to the nature of
the job, one hand or both is in contact with the case most
of the time and so there is little chance for static build
up on the nozzle/your body/brush. Touching the case before
introducing the brush is a good idea.

Personally, I prefer to have the case sat on an esd mat to
leaving it plugged in - not so much from the static point of
view but a marked reluctance to work on anything with power
on or connected, unless unavoidable (like, I don't have the
mat with me).

Not to be done to a laser printer, but for other reasons.

Can you explain why this should not be done to a laser printer,
please.

 

[Franklin]

What do you consider "nasty" about Dishwasher Detergent?

I mean, what harm do you expect?

I have cleaned a LOT of boards in a tub of warm water and
detergent (dishwasher or whatever was handy) with a
paintbrush, it does a great job and the boards worked fine
afterwards, still do. Two important things to do though,
are removing the battery and EPROM first.

What is so special about an EPROM? Surely it is a prone to damage
from water/detergent as the other chips?

 

[keith]

In terms of static, how safe is it to clean inside a home PC by using
a vacuum cleaner?

Some people like this website suggest that it is unwise.
http://www.dansdata.com/sbs3.htm

If my PC is switched off but remains earthed (to the mains earth) and
I am careful not to do physical damage to the PC with my home vacuum
cleaner, then surely there is no problem with static?

Am I overlooking something?

Absolutely! Just because your sysoem is grounded doesn't mean everythign
inside is. Indeed having it grounded could cause even more problems
(current's gotta go somewhere). If you can feel the shock, it''l destroy
any electronics it's going through.

 

[kony]

What is so special about an EPROM? Surely it is a prone to damage
from water/detergent as the other chips?

Perhaps just more sensitive to ESD?
From past experience I've had to reflash BIOS chips that
were left in boards.

 

[Palindr☻me]

Can you explain why this should not be done to a laser printer,
please.

Toner + domestic vacuum cleaner = happy wife*.

*
1) She has probably been nagging to get the old one replaced.

2) Flowers are cheaper and work faster.

 

[Tzortzakakis Dimitrios]

Critical components of my PC have a guarantee of 3 years, which I find long
enough.RAM has a lifetime guarantee.My vendor didn't tell me anything;I find
opening my PCs case doing more harm than good.Even a very small electric
charge on myself can have irreversible effects on the hardware.Computer
circuits are more sensitive to static, than dust (on my opinion anyway).And
to forceful handling (if you allow me the expression).Just my 700 euro worth
(what my PC did cost).

 

[George Macdonald]

Can you explain why this should not be done to a laser printer,
please.

Hmm, since Sue/Palindr?me's response is kinda cryptic, to say the least
(she? seems to prefer flowers?):

1) It can be bad for you - between the developer, which is finely divided
iron beads and the toner, which is an ammonia hydrocarbon complex, there
are various opinions on its carcinogenic effects. Basically a domestic
vacuum cleaner does not have sufficiently small particle filtration in its
bag/trap to prevent throwing the stuff into the air. Note that there are
strict standards now on the amount of leakage of toner/developer from
modern xerographic process printers/copiers - makes me wonder how much
damage was done or identified in the "bad old days".

2) It can be bad for the vacuum cleaner, depending on its construction and
where the bearings and electric motor are relative to the dirty part of the
suction path. When heated, just like in the fusing part of the printing
process, the toner melts and then solidifies into a nasty gunk.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

[Palindr☻me]

Hmm, since Sue/Palindr?me's response is kinda cryptic, to say the least
(she? seems to prefer flowers?):

Sorry, saying that it would cause the vacuum cleaner to stop
working seemed a bit dull. As well as the points you make so
well (below), toner is conductive and will turn the average
brushed-motor into a (short duration) firework display.

I mentally, but apparently not physically, added the
following link:

http://www.tallygenicom.com/support/technotes/misc/page-01.htm

The worst cleaners are, in fact, the small "PC Cleaner"
cheap hand-held jobs. Almost none of these have fine enough
filters (but neither do most domestic vacuum cleaners): but
also they successfully remove the spilt toner from within
the laser printer/copier just to equally successfully
discharge it right into the air the operator is breathing
in. Ideal if your favourite flower arrangement is a wreath.

Yes, she is a she. Yes, she prefers the man in her life to
give her flowers for her birthday and not a new Dyson.(Hint
to he who is reading over shoulder).

 

[Al Dykes]

Hmm, since Sue/Palindr?me's response is kinda cryptic, to say the least
(she? seems to prefer flowers?):

1) It can be bad for you - between the developer, which is finely divided
iron beads and the toner, which is an ammonia hydrocarbon complex, there
are various opinions on its carcinogenic effects. Basically a domestic
vacuum cleaner does not have sufficiently small particle filtration in its
bag/trap to prevent throwing the stuff into the air. Note that there are
strict standards now on the amount of leakage of toner/developer from
modern xerographic process printers/copiers - makes me wonder how much
damage was done or identified in the "bad old days".

2) It can be bad for the vacuum cleaner, depending on its construction and
where the bearings and electric motor are relative to the dirty part of the
suction path. When heated, just like in the fusing part of the printing
process, the toner melts and then solidifies into a nasty gunk.

Rgds, George Macdonald

Using a home VAC can make a g*d-awfull mess if the Vac filter isn't
fine enough to catch the toner, and most vacs are NOT, I'll told.
It just sucks the dust up and plows it all over the room.

The electronic tool supply catalogs sell a special vac for laser
printer cleanup.

 

[George Macdonald]

Sorry, saying that it would cause the vacuum cleaner to stop
working seemed a bit dull. As well as the points you make so
well (below), toner is conductive and will turn the average
brushed-motor into a (short duration) firework display.

I mentally, but apparently not physically, added the
following link:

http://www.tallygenicom.com/support/technotes/misc/page-01.htm

The worst cleaners are, in fact, the small "PC Cleaner"
cheap hand-held jobs. Almost none of these have fine enough
filters (but neither do most domestic vacuum cleaners): but
also they successfully remove the spilt toner from within
the laser printer/copier just to equally successfully
discharge it right into the air the operator is breathing
in. Ideal if your favourite flower arrangement is a wreath.

Yes, she is a she. Yes, she prefers the man in her life to
give her flowers for her birthday and not a new Dyson.(Hint
to he who is reading over shoulder).

Of course you're absolutely right - appliances are *not* presents but just
"necessary" tools of everyday life, though a Dyson is a bit of a luxury for
what it does... just as a Sub-Zero kitchen is also an unnecessary
indulgence. Slippers, socks, ties, basic tools and other items which
men receive as "presents" are in the same category IMO.;-)

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

[George Macdonald]

Using a home VAC can make a g*d-awfull mess if the Vac filter isn't
fine enough to catch the toner, and most vacs are NOT, I'll told.
It just sucks the dust up and plows it all over the room.

Sorry if what I said above was not clear enough on that point.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

[chrisv]

Condensation on your windows merely indicates you've got single
pane glass windows in a climate where double or even triple
panes should be used! (Or that the window isn't shut tightly
enough.)

Well, neither of us is absolutely correct, but I will say that I've
observed condensation, on my double-paned windows, when my ventilator
was off. Never with it on (it's got automatic humistat control),
though.

 

[chrisv]

What kind of climate conditions are you dealing with?

(snip of things I agree with)

What you've described sounds like a seriously faulty vapor
barrier.

c/faulty/normal

True, with careful construction, the problem can be mitigated...

The air-to-air heat exchanger should allow you to
maintain a *higher* relative humidity inside the house than
otherwise would be possible. (Assuming colder outside
temperatures; though perhaps you have exactly the opposite???

Well, no. The humid inside air is vented to the outside, and is
replaced by colder, drier, outside air. Obviously, this lowers the
humidity in the house below what it would be otherwise. I'm not sure
what you're getting at...

 

[Rob Stow]

Well, neither of us is absolutely correct, but I will say that I've
observed condensation, on my double-paned windows, when my ventilator
was off. Never with it on (it's got automatic humistat control),
though.

When it hits -40'C outside I see condensation on my
double pane windows if the RH in my apartment is above
30% - and that seems to be about the norm.

I see static problems when using my mouse and keyboard at
only 30% RH, so I tend to set my humidifier to 35% and
just live with condensation during cold snaps.

People in newer homes here tend to have triple pane
windows and can be condensation-free at -40'C and 40% RH.

Most people around here use humidifiers during the winter
and the rule of thumb for avoiding condensation is to set
it for 30% RH at -40'C and increase the RH by 1% for every
1 degree increase in the outside temperature. That "rule
of thumb" predates the widespread use of home computers and
I have fixed a lot of sporadic computer problems simply by
telling people never to let the RH go below 35% or 40%.



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