Re: What's that black dust in monitors?

[Rod Speed]

Cooked skin mostly (carbonised dust).

Dont believe it. Its too fine for that and the distribution
inside the outer case doesnt fit that either.

 

[Phil Allison]

Dont believe it. Its too fine for that and the distribution
inside the outer case doesnt fit that either.

** All the facts fit.

Electrostatically charged soot consists of very fine particles,
follows air currents and sticks to plastic and metal.





............... Phil

 

[Vermin]

Dont believe it. Its too fine for that and the distribution
inside the outer case doesnt fit that either.

It's not caused by arcing or my Tesla coil would be covered in soot.

http://www.users.bigpond.net.au/broken.trout/DSCF0015.jpg

 

[DarkMatter]

Dont believe it. Its too fine for that and the distribution
inside the outer case doesnt fit that either.

Actually, it is dust from your local region that collects any
moisture in the air after it has been attracted to, and attached to
whatever surfaces of whatever charged devices are in the monitor case.
That would be the HV supply elements, and the tube itself. Then, all
the chassis collects, because it is the return for some of the fields
present. It takes on moisture and gains color. It isn't "baked".

This is why all military CRTs had fully potted HV supplies, and an
oversized anode lead such that less corona is generated, and dust
isn't as big a factor. Next to none on a supply that has a full
faraday cage around it.

 

[DarkMatter]

** All the facts fit.

Electrostatically charged soot consists of very fine particles,
follows air currents and sticks to plastic and metal.

It should actually read "sticks to charged surfaces". They are
usually non-conductors, such as plastic, but conductors that are
isolated from ground can gain charge, and become attractors.

Of course, electrostatically charged elements in a CRT monitor are
the huge capacitive picture tube. Quite a field surrounds them.

 

[Phil Allison]

It should actually read "sticks to charged surfaces".

** I was alluding to the chemical reactivness of soot particles - eg
soot from a fire in a fibreglass PCB leaves dark stains on plated metal
surfaces that cannot be removed with solvents.





............ Phil

 

[Phil Allison]

This is why all military CRTs had fully potted HV supplies, and an
oversized anode lead such that less corona is generated, and dust
isn't as big a factor. Next to none on a supply that has a full
faraday cage around it.

** That may be so unless the air is full of photocopier toner particles -
as when a busy office copier is sited next to the PCs. In the case I saw
all the insides of the monitors and the PC's PSUs with coated in the black
stuff.





............ Phil

 

[CWatters]

Like the Tesla photo. Almost as impressive as this one...

http://hot-streamer.com/ross/Biggg/biggg.htm

 

[DarkMatter]

** I was alluding to the chemical reactivness of soot particles - eg
soot from a fire in a fibreglass PCB leaves dark stains on plated metal
surfaces that cannot be removed with solvents.

http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=pyrolysis>

 

[DarkMatter]

** That may be so unless the air is full of photocopier toner particles -
as when a busy office copier is sited next to the PCs. In the case I saw
all the insides of the monitors and the PC's PSUs with coated in the black
stuff.

Yes, and just like clean dry dust, it is a non conductive,
dielectric even material that will be attracted to any surface that
does not have a net zero charge.

 

[Rod Speed]

All the facts fit.

Nope, dont fit at all. Particularly the distribution
of that black soot on the inside of the monitor case.

It isnt even where the bulk of the airflow happens,
so it cant be where the cooked skin ends up.

Electrostatically charged soot consists of very fine particles,
follows air currents and sticks to plastic and metal.

Yes, but it clearly cant be COOKED SKIN, and
isnt where the airflow happens in a monitor either.

Its always quite close to the FBT,
and so its coming from the FBT plastic.

AND its much worse in a monitor with a failing FBT which
you know is failing because you can hear it clicking and
you're getting the screen image changing when it does.

 

[Rod Speed]

It's not caused by arcing or my Tesla coil would be covered in soot.

Correct, and you dont get that soot with those.

Its gotta be coming from the FBT, because
its always on the case adjacent to that.

Cant be cooked skin either, but that area where
the you get the soot in a monitor isnt usually
where there is all that much airflow thru the case.

The source has to be the epoxy on the FBT.

http://www.users.bigpond.net.au/broken.trout/DSCF0015.jpg

Shit you're ugly, specially those red eyes |-)

 

[Rod Speed]

Actually, it is dust from your local region that collects any moisture
in the air after it has been attracted to, and attached to whatever
surfaces of whatever charged devices are in the monitor case.

Doesnt explain why its black soot.

You certainly get the effect you are talking about on the front
face glass of the monitor and TVs, but its just dust colored.

You also get that effect with those ESD devices that claim to
collect the fine dust out of the air so you dont breath it etc too.

That would be the HV supply elements, and the tube itself. Then,
all the chassis collects, because it is the return for some of the fields
present. It takes on moisture and gains color. It isn't "baked".

That black soot you get inside a monitor case close to
the FBT certainly isnt just dust, its black/very dark grey.

Nothing like the brownish/reddish dust we get so much of around here.

This is why all military CRTs had fully potted HV supplies,
and an oversized anode lead such that less corona is
generated, and dust isn't as big a factor. Next to none
on a supply that has a full faraday cage around it.

It isnt dust. Its much too black for that.

 

[Rod Speed]

That may be so unless the air is full of photocopier toner
particles - as when a busy office copier is sited next to the PCs.

Sure but this is a red herring. Most home PCs dont
have any photocopiers around at all, and you still get
that black soot in all the monitors used in the home.

And its not cigarette smoke either. Thats got a
characteristic stink to it so you can tell which PCs
are used by smokers as soon as you open them.
Presumably its the tars you are smelling.

In the case I saw all the insides of the monitors
and the PC's PSUs with coated in the black stuff.

Yes, but you still get that with monitors that have
never ever been used anywhere near any photocopier.

 

[Vermin]

-snip-

Cant be cooked skin either, but that area where
the you get the soot in a monitor isnt usually
where there is all that much airflow thru the case.

The source has to be the epoxy on the FBT.


Shit you're ugly, specially those red eyes |-)

That's not me dumbass.
====================
Fucking stupid niggers keep askin for me bank account.

 

[Vermin]

Like the Tesla photo. Almost as impressive as this one...

http://hot-streamer.com/ross/Biggg/biggg.htm

Bet that annoyed the neighbors

 

[Rod Speed]

Rod Speed [email protected] wrote

That's not me dumbass.

Corse you would claim that now, dumbarse.

 

[DarkMatter]

Its gotta be coming from the FBT, because
its always on the case adjacent to that.

That is also where the most field is. DOH! Follow the HV pathways,
and generating element, and one will find where the most proliferant
accumulations of particulate are. They don't come *from* the flyback,
they collect around it, and other of the HV elements in the system.

 

[DarkMatter]

And its not cigarette smoke either. Thats got a
characteristic stink to it so you can tell which PCs
are used by smokers as soon as you open them.
Presumably its the tars you are smelling.

Yes. It is the tars that have accumulated on the dust that has
accumulated on the charged surfaces inside the monitor.

A smoker actually reduces his CRT lifespan in his home for this
reason. It blankets things such that they don't dissipate their
generated heat as well, leading to pre-mature failure.

 

[DarkMatter]

Corse you would claim that now, dumbarse.

Since we are in a High Voltage group, you are an idiot.