PC Smoke

And what makes them red hot ?

Power dissipation. Too much of it caused by too much voltage across it which causes too much current to flow which causes too much wattage to need to dissipate which raises the temperature.

Resistors do not lower in value unless abused. Even then, more than half the time they open up.

I really screwed up before thinking this was a laptop, but in a desktop if something actually burns on the motherboard it is almost always a power supply that went open loop and threw too much voltage at it.

Still, one of the USB devices could have been shorted. That is a possibility. He might have just got it set up to copy when it just couldn't take anymore, because it is not that likely that accessing it would cause a short.

I think it highly possible that this is a case where the power supply coincidentally occurred at that time. If that's the case, it is already fried.

You are aware that first alert is owned by kiddie now right? they put out units under each name and with varying prices. just like most THINK FIREX is junk WRONG its also owned by kiddie. As for the resistor it was a big one in a thousand watt gaming power supply and let me tell you between it buring up and the plastic around it from the heat it created it was a nice smoky mess:)

The other day an UNUSED! SATA connector in my desktop computer shorted out at the free end filling the room with smoke and shutting down the computer.

You can do a Google image search for "burned SATA connector" and see the type of damage I had.

Fairly common problem, apparently.

Mark Z.

That is progress.

No, I wasn't aware of that. Looking at the Wikipedia page, First Alert seems to be owned by Jarden Branded Consumables. No mention of Kidde.

The Kidde page shows that they're part of UTC (United Technologies Corporation) as UTC Fire & Security. No mention of First Alert.

I don't have time right now to chase down the details, but it seems to me that they're seperate and unrelated companies. Are you sure?

Yep. Firex is part of Kiddie: Looks like they're recommending total replacent of anything labeled Firex.

Ok, that's different. Big power can generate plenty of smoke. I would expect a smoke alarm to respond fairly quickly to a "nice smoky mess". You also won't need a vinyl hose "sniffer" to find the source. Just look for the crater when the smoke clears.

Most resistor types go high when overheated which limits the potential for damage.

Glass cored resistors cause an increase in current and consequently the potential for damage.

Good idea will give me something to do later:)

As far as i know unless it was sold again first alert is owned or WAS OWNED by kiddie

I remember a video on the internet about having some "fun" with a microwave . Normally you put glass in a microwave it is unaffected. Well they took a torch to it and heated it up first and then it was definitely affected by m icrowaves. Before that I never knew glass becomes conductive at high temper atures.

Most types of glass are lossy enough at microwave to not need any such preparation.

Once I put a TV valve (tube) in the microwave, the glass glowed red and became plastic, it wrapped around the internal structure like cling film.

My coffee mug is glass - I have to tuck the handle into a corner when I heat a cup of water, otherwise the handle gets hot and burns my hand.

The alumina ceramic on a spark plug is also lossy enough to get red hot.

I believe you, but............how do you know? It's darned hard to get the ceramic off the steel part before I put it in the microwave.

I was cleaning the plugs - they wouldn't have been much use if I'd removed the metal bit.

If you leave a plug overnight in an industrial strength ultrasonic cleaner, it loosens the compacted powder seal - put it in an engine and the seal will blow out within a mile.

If I want the metal shell to make a 2-stroke TDC measure, I just grind off the rolled down lip and dig the seal out with a small screwdriver.