Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers etc

http://www.sunderlandecho.com/news/S...-in.3844143.jp

http://www.thisislondon.co.uk/news/a...yhem+as+neighb
ours'+digiboxes+all+burst+into+flames+at+once+due+ to+power+surge/article.do

Mayhem as neighbours' digiboxes all burst into flames at once due to power
surge
Last updated at 07:37am on 06.03.08

A massive power surge triggered a number of TV digiboxes to burst into
flames on one street as firefighters dashed from house to house.

The set-top boxes began spitting sparks and residents living on the street
described the road as being "lit up like Blackpool Pier".

Firefighters had to go from house to house asking people to unplug their
electrical items as panicked home-owners ran into the street.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N Cook" wrote in message
...
Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers
etc

http://www.sunderlandecho.com/news/S...-in.3844143.jp

http://www.thisislondon.co.uk/news/a...yhem+as+neighb
ours'+digiboxes+all+burst+into+flames+at+once+due+ to+power+surge/article.do

Mayhem as neighbours' digiboxes all burst into flames at once due to power
surge
Last updated at 07:37am on 06.03.08

A massive power surge triggered a number of TV digiboxes to burst into
flames on one street as firefighters dashed from house to house.

The set-top boxes began spitting sparks and residents living on the street
described the road as being "lit up like Blackpool Pier".

Firefighters had to go from house to house asking people to unplug their
electrical items as panicked home-owners ran into the street.



I would guess that a lot of it is just 'newsrag speak' to sensationalise an
unusual, but otherwise mundane event. It's hard to see from the picture just
what has burnt, but I'd be surprised if the boxes were catching light as a
result of some internal failure, before the fuse blew. If they did, and
there was a genuine risk to life and property, then the manufacturers need
to take a very serious look at the materials they are using in the box, and
what can be done to minimise the risk. It doesn't say exactly what sort of
'digiboxes' these are, but I would guess that they are probably 'electrical
barn' and supermarket Freeview boxes that are made in China, and cost 20
quid retail. If that is the case, then trading standards need to investigate
the reasons, and get them withdrawn, if there is an issue.

As to why the digiboxes rather than other devices. Who can tell? About all
that I can say is that the power supplies are pretty small, and everything
is rated to run by the skin of its teeth in the first place, so it doesn't
take much out of the ordinary to fry them. One such supply that I work on,
for instance, is a complete standby supply in a little 7 pin DIL chip. Now
380v flying around in a chip that size, just ain't right ...

The supplies used in TV sets and computers and so on, tend to be a bit more
robust, and many other wallwart supplies are still linears, although I will
grant you that a substantial number are now switchers, and any that were
plugged in may well have also been fried by whatever caused this
'newsworthy' event, but the owners would not have seen anything, as they are
completely enclosed.

Arfa

Arfa Daily wrote:
"N Cook" wrote in message
...
Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers
etc

http://www.sunderlandecho.com/news/S...-in.3844143.jp

http://www.thisislondon.co.uk/news/a...yhem+as+neighb
ours'+digiboxes+all+burst+into+flames+at+once+due+ to+power+surge/article.do

Mayhem as neighbours' digiboxes all burst into flames at once due to power
surge
Last updated at 07:37am on 06.03.08

A massive power surge triggered a number of TV digiboxes to burst into
flames on one street as firefighters dashed from house to house.

The set-top boxes began spitting sparks and residents living on the street
described the road as being "lit up like Blackpool Pier".

Firefighters had to go from house to house asking people to unplug their
electrical items as panicked home-owners ran into the street.



I would guess that a lot of it is just 'newsrag speak' to sensationalise an
unusual, but otherwise mundane event. It's hard to see from the picture just
what has burnt, but I'd be surprised if the boxes were catching light as a
result of some internal failure, before the fuse blew. If they did, and
there was a genuine risk to life and property, then the manufacturers need
to take a very serious look at the materials they are using in the box, and
what can be done to minimise the risk. It doesn't say exactly what sort of
'digiboxes' these are, but I would guess that they are probably 'electrical
barn' and supermarket Freeview boxes that are made in China, and cost 20
quid retail. If that is the case, then trading standards need to investigate
the reasons, and get them withdrawn, if there is an issue.

As to why the digiboxes rather than other devices. Who can tell? About all
that I can say is that the power supplies are pretty small, and everything
is rated to run by the skin of its teeth in the first place, so it doesn't
take much out of the ordinary to fry them. One such supply that I work on,
for instance, is a complete standby supply in a little 7 pin DIL chip. Now
380v flying around in a chip that size, just ain't right ...

The supplies used in TV sets and computers and so on, tend to be a bit more
robust, and many other wallwart supplies are still linears, although I will
grant you that a substantial number are now switchers, and any that were
plugged in may well have also been fried by whatever caused this
'newsworthy' event, but the owners would not have seen anything, as they are
completely enclosed.

Arfa


But Arfa, the whole road was lit up like Blackpool Pier! Shirley no one
would make that up?



Ron

On Mar 6, 9:05 am, "N Cook" wrote:
Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers etc

bad or lazy reporting, sounds like second hand information to me.

whilst i suppose with the newer cheaply made stuff it is not
impossible for there to be some burnup, on the devices i have repaired
which had suffered surges, 99% of the time a resistor or transformer
primary in the power supply had opened up before any fireworks. even
the traces on the pcb had gone o/c on a couple of items...

-B

Arfa Daily wrote in message
...

"N Cook" wrote in message
...
Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers
etc


http://www.sunderlandecho.com/news/S...-in.3844143.jp


http://www.thisislondon.co.uk/news/a...yhem+as+neighb

ours'+digiboxes+all+burst+into+flames+at+once+due+ to+power+surge/article.do

Mayhem as neighbours' digiboxes all burst into flames at once due to
power
surge
Last updated at 07:37am on 06.03.08

A massive power surge triggered a number of TV digiboxes to burst into
flames on one street as firefighters dashed from house to house.

The set-top boxes began spitting sparks and residents living on the
street
described the road as being "lit up like Blackpool Pier".

Firefighters had to go from house to house asking people to unplug their
electrical items as panicked home-owners ran into the street.



I would guess that a lot of it is just 'newsrag speak' to sensationalise
an
unusual, but otherwise mundane event. It's hard to see from the picture
just
what has burnt, but I'd be surprised if the boxes were catching light as a
result of some internal failure, before the fuse blew. If they did, and
there was a genuine risk to life and property, then the manufacturers need
to take a very serious look at the materials they are using in the box,
and
what can be done to minimise the risk. It doesn't say exactly what sort of
'digiboxes' these are, but I would guess that they are probably
'electrical
barn' and supermarket Freeview boxes that are made in China, and cost 20
quid retail. If that is the case, then trading standards need to
investigate
the reasons, and get them withdrawn, if there is an issue.

As to why the digiboxes rather than other devices. Who can tell? About all
that I can say is that the power supplies are pretty small, and everything
is rated to run by the skin of its teeth in the first place, so it doesn't
take much out of the ordinary to fry them. One such supply that I work on,
for instance, is a complete standby supply in a little 7 pin DIL chip. Now
380v flying around in a chip that size, just ain't right ...

The supplies used in TV sets and computers and so on, tend to be a bit
more
robust, and many other wallwart supplies are still linears, although I
will
grant you that a substantial number are now switchers, and any that were
plugged in may well have also been fried by whatever caused this
'newsworthy' event, but the owners would not have seen anything, as they
are
completely enclosed.

Arfa



I know someone who was up at 3am when his street was affected by such a
surge, blew the room lamp and hall lamp after glowing like floodklights and
breaking TV. stereo etc but nothing caught fire.

I was most impressed by this local ITV coverage, yesterday or day before, of
this sort of matter.
Including showing the internals of a SMPS with just 1mm between live and
consumer side pcb tracks. Informative and quite technical

My browser corrupts this site but URL something like
http://www.meridiantv.com/info/chargers.shtml

Top tips for avoiding unsafe chargers and adaptors

[i-charger]Most of us plug in, switch on and charge up everyday but with
millions of cheap, substandard copies of the latest gadgets and gizmos
available online it could actually be our lives that we're playing with.

An exclusive investigation by our consumer team has revealed that many items
bought from online auction sites can prove so hazardous, they have the
potential to kill.

Our consumer team bought a random selection of chargers - some for as little
as 49 pence. We took them along to Nemko's safety testing labarotory in
London, where they all failed on a purely visual inspection but it was
during more thorough testing procdeures that a frightening catalogue of
flaws was revealed.

We have asked Nemko's Melvyn Harries, who tested our chargers, to give
viewers some tips for spotting a fake - and avoiding potential danger.
Here's his advice:


Top tips for avoiding unsafe chargers and adaptors
1 Buy from a reputable retailer.
2

If the product itself is not marked with a brand name/logo and model
name/number, be suspicious.
3 There should be a 9.5mm gap between the live/neutral pins and the edge of
the plug body.
[i-plug1] [i-plug2]
As a quick check, place your little finger against the plug pin and you
should still be able to see the edge of the plug.
[i-plug3] [i-plug4]
4 On the socket part of an adaptor the live and neutral contacts should be
covered by shutters. If there are no shutters and you can see the
live/neutral contacts, the product is unsafe (see picture).


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

b wrote in message
...
On Mar 6, 9:05 am, "N Cook" wrote:
Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers
etc

bad or lazy reporting, sounds like second hand information to me.

whilst i suppose with the newer cheaply made stuff it is not
impossible for there to be some burnup, on the devices i have repaired
which had suffered surges, 99% of the time a resistor or transformer
primary in the power supply had opened up before any fireworks. even
the traces on the pcb had gone o/c on a couple of items...

-B

As i said in the other reply
I know someone who was up at 3am when his street was affected by such a
surge, blew the room lamp and hall lamp after glowing like floodklights and
breaking TV, stereo etc but nothing caught fire.

I don't know what you call it because it is oxymoronic, but a slow surge.
The first he knew about it was the living room bulb got noticeably brighter
and then over 10 seconds or so grew brighter and brighter until it blew,
followed by the hall one and then he noticed all the other stuff was no
longer working, as he was only reading at the time.

A slow voltage increase would allow things to overheat before any fuses
blew.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N Cook" wrote in :

Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers
etc

Perhaps all the digiboxes were fed from the same cable leg and someone
dropped a HT line onto the cable shield.
Or dropped the cable shield onto an HT feed?



http://www.sunderlandecho.com/news/S...ted-in.3844143.
jp

http://www.thisislondon.co.uk/news/a.../Mayhem+as+nei
ghb
ours'+digiboxes+all+burst+into+flames+at+once+due+ to+power+surge/article.
do

Mayhem as neighbours' digiboxes all burst into flames at once due to
power
surge
Last updated at 07:37am on 06.03.08

A massive power surge triggered a number of TV digiboxes to burst into
flames on one street as firefighters dashed from house to house.

The set-top boxes began spitting sparks and residents living on the
street described the road as being "lit up like Blackpool Pier".

Firefighters had to go from house to house asking people to unplug their
electrical items as panicked home-owners ran into the street.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/















--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

Arfa Daily wrote:

I would guess that a lot of it is just 'newsrag speak' to sensationalise an
unusual,

Very much so.


but otherwise mundane event. It's hard to see from the picture just
what has burnt, but I'd be surprised if the boxes were catching light as a
result of some internal failure, before the fuse blew. If they did, and
there was a genuine risk to life and property, then the manufacturers need
to take a very serious look at the materials they are using in the box, and
what can be done to minimise the risk.

It would also almost certainly fail to meet EN60065 and would therefore be
illegal.

Graham

N Cook wrote:

I was most impressed by this local ITV coverage, yesterday or day before, of
this sort of matter.
Including showing the internals of a SMPS with just 1mm between live and
consumer side pcb tracks. Informative and quite technical

Are you SURE about that 1mm ? Was it REALLY between primary and secondary parts
? That's a straight EN60065 failure and hence illegal to be sold in any part of
the EU.

Graham

N Cook wrote:

I know someone who was up at 3am when his street was affected by such a
surge, blew the room lamp and hall lamp after glowing like floodklights and
breaking TV, stereo etc but nothing caught fire.

Good. That's what EN60065 requires.

Graham

" wrote:

"N Cook" wrote:

Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers etc

Are these digital boxes for cable TV or Satellite TV?

They were for cable I think.

Graham

"Eeyore" wrote in message
...


" wrote:

"N Cook" wrote:

Assuming mains neutral fault and not lightning strike.
Why just digiboxes bursting into flames , not TVs , cell phone chargers
etc

Are these digital boxes for cable TV or Satellite TV?

They were for cable I think.

Graham



If that is the case, and they really did fail in the way described in the
article, then the cable operator would need to be dragged into it as well,
as STBs for cable are necessarily supplied by the cable operator. Likewise
for satellite TV, assuming Sky, although you can of course buy those
yourself. Most people don't, however, because of the price deals offered by
Sky, which include the box and installation. Plus these boxes are only made
by a few highly reputable main players in the market such as Pace and
Panasonic and Grundig etc. That was why I figured that these might well be
Freeview boxes for TDTV, as digital is being forced on an unsuspecting
public by the government, and punters are being driven like sheep by TV ads,
to get converted for digital. And how do they do that ? With a Mickey Mouse
twenty quid Chinese box about the size of a paperback book, bought from the
local supermarket ...

Arfa