Plugged in a network cable today from a 803.af poe switch and it started
smoking.

Looked on the board and several SMD transistors near the network socket
have fried.

I can't see any isolating transformers!

On 26/12/15 19:10, dennis@home wrote:
Plugged in a network cable today from a 803.af poe switch and it started
smoking.

Looked on the board and several SMD transistors near the network socket
have fried.

I can't see any isolating transformers!

they look like ...SMD transistors..


--
the biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.

On 26/12/2015 19:41, The Natural Philosopher wrote:
On 26/12/15 19:10, dennis@home wrote:
Plugged in a network cable today from a 803.af poe switch and it started
smoking.

Looked on the board and several SMD transistors near the network socket
have fried.

I can't see any isolating transformers!

they look like ...SMD transistors..



Not with three legs they don't.

On 26/12/15 23:17, dennis@home wrote:
On 26/12/2015 19:41, The Natural Philosopher wrote:
On 26/12/15 19:10, dennis@home wrote:
Plugged in a network cable today from a 803.af poe switch and it started
smoking.

Looked on the board and several SMD transistors near the network socket
have fried.

I can't see any isolating transformers!

they look like ...SMD transistors..



Not with three legs they don't.

Just kidding. Usually built into the actual socket these days.

http://www.pulseelectronics.com/products/lan

--
the biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.

En el artículo , The Natural Philosopher
escribió:

Just kidding. Usually built into the actual socket these days.

Often left out (socket without isolating transformers fitted) to save
money. The first batch of Raspberry Pis had to be recalled and reworked
for this reason.

--
(\_/)
(='.'=) Bunny says: Windows 10? Nein danke!
(")_(")

Come on now, nobody produces a live chassis item with connectors that can be
used like that. the problem has to be something in the device. What has it
done to the other end, whatever was plugged in?
Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"dennis@home" wrote in message
web.com...
Plugged in a network cable today from a 803.af poe switch and it started
smoking.

Looked on the board and several SMD transistors near the network socket
have fried.

I can't see any isolating transformers!

On Sun, 27 Dec 2015 07:36:42 +0000, The Natural Philosopher wrote:

On 26/12/15 23:17, dennis@home wrote:
On 26/12/2015 19:41, The Natural Philosopher wrote:
On 26/12/15 19:10, dennis@home wrote:
Plugged in a network cable today from a 803.af poe switch and it
started smoking.

Looked on the board and several SMD transistors near the network
socket have fried.

I can't see any isolating transformers!

they look like ...SMD transistors..



Not with three legs they don't.

Just kidding. Usually built into the actual socket these days.

http://www.pulseelectronics.com/products/lan

Yes, remember the production problem with the early Raspberry Pis.

On 27/12/2015 10:34, Brian-Gaff wrote:
Come on now, nobody produces a live chassis item with connectors that can be
used like that. the problem has to be something in the device. What has it
done to the other end, whatever was plugged in?
Brian


Nothing as it is designed properly with isolation as required.

For all I know the TV has isolation but it obviously failed as there
should be no way to do damage plugging in a poe switch rather than a non
poe switch.

I emailed Samsung and they have asked me to contact their service centre
so I will do that Monday and see what they have to say.

The damn thing still works as a TV (no HD tuner) but the hdmi and
ethernet no longer work which makes it pretty useless to me.

In article ,
Brian-Gaff wrote:
Come on now, nobody produces a live chassis item with connectors that
can be used like that. the problem has to be something in the device.
What has it done to the other end, whatever was plugged in?

I don't think there has been a live chassis TV etc produced for decades.
That practice really ended with all transistor designs - and of course the
ability to connect an external device like the first VCRs, other than via
the aerial socket.

--
*Save the whale - I'll have it for my supper*

Dave Plowman London SW
To e-mail, change noise into sound.

dennis@home wrote:

I can't see any isolating transformers!

In which case they /should/ be built in to the metal can of the socket
.... unless someone slipped up and specced the type of socket that
expects the magnetics to be housed separately on the PCB ...

Mike Tomlinson wrote:
Often left out (socket without isolating transformers fitted) to save
money. The first batch of Raspberry Pis had to be recalled and reworked
for this reason.

'Often'? Just curious because I haven't seen this before. AIUI the
transformer is used to bias the NIC side and filter out common mode signals
so you can't simply omit it, though perhaps something could be faked up with
Rs and Cs.

The Pi issue was because the manufacturer was being dumb and substituted a
non-magnetics RJ45 for an integrated magnetics one - that's just a stupid
procurement decision, I don't imagine the Pi ethernet actually worked in
that state.

Magnetic-less ethernet does exist, in standards like 1000Base-KX and
10GBase-KR where it is a backplane interconnect. You need a different PHY for
that, though.

I wouldn't be surprised if some unfortunate device manufacturer grounded
unused pins on their RJ45 'to reduce noise' - which causes fireworks when
PoE is attached.

Theo

dennis@home wrote:
On 26/12/2015 19:41, The Natural Philosopher wrote:
On 26/12/15 19:10, dennis@home wrote:
Plugged in a network cable today from a 803.af poe switch and it started
smoking.

Looked on the board and several SMD transistors near the network socket
have fried.

I can't see any isolating transformers!

they look like ...SMD transistors..



Not with three legs they don't.

They may be transient voltage suppressors (which absorb voltage spikes - up
to a point). They can come in three legged SMD packages that you can't tell
apart from transistors.

Does it still work after the smoke? It isn't strictly necessary to have
TVSes, though it probably won't pass EMC/noise immunity and be more
susceptible to further damage from spikes.

Can you take a picture?

Theo

In article ,
Mike Tomlinson writes:
En el artículo , The Natural Philosopher
escribió:

Just kidding. Usually built into the actual socket these days.

Often left out (socket without isolating transformers fitted) to save
money. The first batch of Raspberry Pis had to be recalled and reworked
for this reason.

That was a mistake, not a design choice.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

En el artículo , Andrew Gabriel
escribió:

That was a mistake, not a design choice.

I know, I didn't imply otherwise. They recalled them and fitted the
correct part.

--
(\_/)
(='.'=) Bunny says: Windows 10? Nein danke!
(")_(")