Ask MetaFilter questions tagged with static

I can hear the ocean

uncleozzy — Thu, 05 Nov 2009 06:48:01 -0800

You are not my amp tech, but maybe you can help me diagnose the source of a strange noise on a brand new guitar amp. Yesterday, I got a tiny tube amp in the mail. After letting it come up to room temperature, I plugged it into a cab (yes, with the right impedance) and played away. No problems at all; made some really nice sounds, by the way.

The next time I turned it on (an hour or two later), there was an awful static noise--sort of like rushing water, or waves crashing--even with the volume all the way down and no guitar attached. Playing through it produced pops and crackles and unpredictable volume changes, and the static continued.

It's got 2 12AX7 tubes (and a funky setup--V1 and one triode of V2 are the preamp, and the other triode on V2 is the power tube). Best I can tell (which is not saying much), they both look normal, glow a healthy orange, aren't microphonic.

Now, the head is brand new, so there's a really good chance it's going back to the vendor as defective, but out of curiosity (and future diagnostic needs), what could the problem be?

Speaker noise when metal USB plug touches my computer case and other electrical problems.

archagon — Sun, 01 Nov 2009 16:21:09 -0800

Speaker noise when metal USB plug touches my computer case and other electrical problems. I have an aluminum PC case. Whenever the metal USB plug from my external drive contacts the front, I get crackling from my speakers, which are connected to an external USB soundcard. (This crackling happens even if they're not connected to the actual output jack.) A few possibly related problems: my audio occasionally starts popping once every few minutes, and my USB devices sometimes play the "connected" sound in Windows even though they're already connected, as if they're briefly disconnecting.

My guess is that this has to do with the grounding, but I'm not sure exactly what to do. My case has a round grounding wire, but I don't know where to attach it, and fiddling with it didn't seem to have any effect. Suggestions?

WTF was that?!

kmz — Fri, 16 Oct 2009 23:36:05 -0800

My fiancee and I were just now woken up by the sound of a large explosion right in our bedroom. Almost like a gunshot but not quite that loud. And I think I saw a flash of light. Both seemed to come from near the ceiling by the door. I turned on one of the lights but there's no residue I can see from anything. Nothing seems to be broken in terms of lights or circuits. Was it some kind of giant static discharge? It scared the shit out of us and definitely isn't helping with the both of us bedridden with flu thing.

static electricty problem

1joseywales — Wed, 16 Sep 2009 06:40:01 -0800

Would a faraday cage protect sensetive electronic equipment from ambiant static electricty during a lightning storm?

Are we being punked?

Tallguy — Tue, 18 Aug 2009 08:53:37 -0800

In order to fix a malfunctioning printer we have been told to unplug it and hold down the power button for one minute to release static. Are we being punked? My wife is working through the scripted advice generated by HP on addressing an ink jet printer that is not functioning correctly. Most of the steps are to be expected (clean rollers, check paper feeds, etc.) They also ask her to unplug the power and USB cable and hold down the power button for 1 minute to release static. That was the first I ever heard of using that as a fix. When I google it, there are people who recommend it for fixing other electronic devices such as laptops that won't boot (first remove the battery then hold the power button for 1 minute).

Does this actually do anything or is it electronic device voodoo? Where is this static that is supposedly being released and how does holding the power button release it? And since the device is unplugged and is not grounded where is this static going? I am not an electronics expert and I would love to hear from those who are.

I need to keep my hard drive safe from the elements.

pemberkins — Tue, 14 Jul 2009 14:23:51 -0800

Will I completely ruin my hard drive if I don't store it in an anti-static bag? I need to mail off my laptop for repairs. I was told that I did not need to send in the hard drive with the rest of the laptop. This is great, because I'd rather not take the risk of accidentally losing everything in transit or at the hands of a wayward repair technician.

However, I can't for the life of me find any anti-static bags in the house. I need to mail off the laptop soon, so ordering anti-static bags off the internet is not an option - I wouldn't get them fast enough.

Is there another safe way to store my hard drive for a week or so, or am I out of luck? (That is, is it riskier to store the hard drive at home, NOT in an anti-static bag, than it is to leave the hard drive inside the laptop and ship the whole thing out?)

What causes electronics to stop working when exposed to static electricity or water? (with misc electronics questions)

laptolain — Fri, 03 Apr 2009 21:59:56 -0800

What causes electronics to stop working when exposed to static electricity or water? (with misc electronics questions) I'm looking for an informative layman's explanation of the above question.

Also, I'm really interested in soldering electronics as a hobby. I've had many false starts with this and I think it's because I always end up reading reference or technical books. I think it was MAKE that had videos about the history of the LED and resistor that I really enjoyed but haven't found anything similar since.

My main goal is the ability to identify the function of common parts on a PCB. I think that will pique my curiosity and I'll naturally dig deeper.

I'm also confused about basic electronics vs processing chips. Are all processors created for a specialized purpose? Could you take a sound processor or a GPU out of a computer and then re-purpose it into your hobbyist work? Can you interface with any processor through software easily? Is it even worth doing this if you don't know any programming languages? It seems like the more interesting aspects of electronics beyond simple open/closed circuit motor kits require programming. I'm not against learning a programming language in fact I'd love an excuse to but I just want to understand what being an electronics hobbyist means.

I learn new things fast but it requires I find information in this counter intuitive format. If you have any websites or books you think would help I would really appreciate it.

Thanks!

How to fix C++ static linking problems?

duoshao — Thu, 26 Mar 2009 06:33:33 -0800

I need some help diagnosing a problem static linking a C++ program using g++. It compiles and runs just fine without "-static", but I get all sorts of "undefined references" errors when I use "-static". I'm a C++ novice and am at a loss. Can anyone throw me a bone? I'm using g++ v4.32 running on Debian Lenny.

As I said, it compiles, links, and runs with no problem using dynamic linking. It just breaks with "-static". This is also why I didn't post the source code, though I can if it would be helpful.

Aside from the standard C++ stuff (iostream, ifstream), I'm only using the vmime library and two libraries that it requires (gsasl and gnutls). I installed gsasl and gnutls using apt-get, but I built libvmime from source with no errors. Libvmime's ./configure defaults to building both static and dynamic versions of the library, and I've confirmed that both libvmime.a and libvmime.o exist. I also confirmed that .a files exist for both gsasl and gnutls.

Here's my compile command line:
g++ `pkg-config --cflags --libs vmime` -static -o mimetest mimetest.cpp

The pkg-config bit expands to:
-I/usr/local/include/ -L/usr/local/lib -lvmime -lgnutls -lgsasl

I've confirmed that libvmime exists under /usr/local/lib, and gnutls and gsasl exist under /usr/lib.

I've posted the errors below. Any suggestions?

Thanks,
M
------------------------------------------------------------------------------

/tmp/ccioHkjN.o: In function `loadX509CertificateFromFile(std::basic_string, std::allocator > const&)':
mimetest.cpp:(.text+0x140): undefined reference to `vmime::utility::inputStreamAdapter::inputStreamAdapter(std::basic_istream >&
)'
mimetest.cpp:(.text+0x15d): undefined reference to `vmime::security::cert::X509Certificate::import(vmime::utility::inputStream&)'
/tmp/ccioHkjN.o: In function `main':
mimetest.cpp:(.text+0x2681): undefined reference to `vmime::security::cert::defaultCertificateVerifier::setX509RootCAs(std::vector, std::allocator > > const&)'
mimetest.cpp:(.text+0x2703): undefined reference to `vmime::net::session::getProperties()'
mimetest.cpp:(.text+0x27f5): undefined reference to `vmime::net::session::getProperties()'
mimetest.cpp:(.text+0x28dd): undefined reference to `vmime::net::session::getProperties()'
mimetest.cpp:(.text+0x29c8): undefined reference to `vmime::net::session::getProperties()'
mimetest.cpp:(.text+0x2ab2): undefined reference to `vmime::utility::url::url(std::basic_string, std::allocator > const&)'
mimetest.cpp:(.text+0x2b5c): undefined reference to `vmime::net::session::getStore(vmime::utility::url const&, vmime::utility::ref)'
mimetest.cpp:(.text+0x2c0b): undefined reference to `vmime::net::service::setCertificateVerifier(vmime::utility::ref)'
mimetest.cpp:(.text+0x2d60): undefined reference to `vmime::charsets::UTF_8'
mimetest.cpp:(.text+0x2d72): undefined reference to `vmime::charset::charset(char const*)'

----------------------------------------------------------------
Cut out some...
----------------------------------------------------------------

/tmp/ccioHkjN.o: In function `vmime::header::Date() const':
mimetest.cpp:(.text._ZNK5vmime6header4DateEv[vmime::header::Date() const]+0x1b): undefined reference to `vmime::fields::DATE'
mimetest.cpp:(.text._ZNK5vmime6header4DateEv[vmime::header::Date() const]+0x4a): undefined reference to `vmime::header::findField(std::basic_string, std::allocator > const&) const'
/tmp/ccioHkjN.o: In function `vmime::header::From() const':
mimetest.cpp:(.text._ZNK5vmime6header4FromEv[vmime::header::From() const]+0x1b): undefined reference to `vmime::fields::FROM'
mimetest.cpp:(.text._ZNK5vmime6header4FromEv[vmime::header::From() const]+0x4a): undefined reference to `vmime::header::findField(std::basic_string, std::allocator > const&) const'
/tmp/ccioHkjN.o: In function `vmime::header::Subject() const':
mimetest.cpp:(.text._ZNK5vmime6header7SubjectEv[vmime::header::Subject() const]+0x1b): undefined reference to `vmime::fields::SUBJECT'
mimetest.cpp:(.text._ZNK5vmime6header7SubjectEv[vmime::header::Subject() const]+0x4a): undefined reference to `vmime::header::findField(std::basic_string, std::allocator > const&) const'
/tmp/ccioHkjN.o: In function `vmime::charset::~charset()':
mimetest.cpp:(.text._ZN5vmime7charsetD1Ev[vmime::charset::~charset()]+0xd): undefined reference to `vtable for vmime::charset'
mimetest.cpp:(.text._ZN5vmime7charsetD1Ev[vmime::charset::~charset()]+0x2c): undefined reference to `vmime::component::~component()'
mimetest.cpp:(.text._ZN5vmime7charsetD1Ev[vmime::charset::~charset()]+0x50): undefined reference to `vmime::component::~component()'
/tmp/ccioHkjN.o: In function `vmime::utility::url::~url()':
mimetest.cpp:(.text._ZN5vmime7utility3urlD1Ev[vmime::utility::url::~url()]+0x12): undefined reference to `vmime::propertySet::~propertySet()'
/tmp/ccioHkjN.o:(.rodata._ZTVN5vmime7utility11inputStreamE[vtable for vmime::utility::inputStream]+0x10): undefined reference to `vmime::utility::stream::get
BlockSize() const'
/tmp/ccioHkjN.o:(.rodata._ZTIN5vmime7utility11inputStreamE[typeinfo for vmime::utility::inputStream]+0x8): undefined reference to `typeinfo for vmime::utilit
y::stream'
collect2: ld returned 1 exit status

Video killed my audio stars

larsks — Mon, 16 Feb 2009 16:43:45 -0800

Plugging in an external monitor to my Macbook Pro kills the audio. What's up with that? And is there a solution that does not involve an expensive USB audio product? My Macbook Pro is attached to a stereo system, which has worked just fine and dandy...until I plugged in a DVI cable and suddenly the audio was almost overwhelmed by static and "machine noise" (e.g., there are changes in the sound when I press keys or scroll windows). I usually associate this with poor shielding on cheap sound cards...what's up with my Macbook?

More importantly, is there anything I can do to fix this? I'd really like to be able to use an external monitor. One solution is some sort of external USB-connected audio device, but I'm not entirely sure what my options are...the only things I've found are (a) headphones, when what I really want is 1/8" stereo out, or (b) audio input devices like the M-Audio FastTrack (which also support audio out). I don't want just headphones, and I don't need anything as fancy as the USB connected devices I've found.

Thanks for your suggestions!

How do I easily convert an ASP.Net 2.0 website to plain html?

therubettes — Wed, 14 Jan 2009 04:37:45 -0800

Is it possible to use Visual Web Developer 2005 Express Edition to create a simple website and to then easily convert the site to plain html? I have to put together a simple website, about 20 pages of static content. I would like to use Visual Web Developer 2005 Express Edition as it has lots of neat functionality that will allow me to build and amend the site quickly e.g. sitemap, masterpages, navigation controls etc.

How would I then go about automating the process of exporting the site to a static version (by this I mean plain HTML) i.e. one that will function on my webhost?

To clarify I will not be using any of the fancy .net functionality or controls. So no logins, calenders, datagrids, database etc. The thing wont even have a radiobutton!

Oh and if you think this is a dumb idea please tell me.

How to prevent plastic roll static shocks?

attercoppe — Thu, 25 Sep 2008 13:33:40 -0800

How can I ground a large roll of plastic wrap to prevent static electric shocks when unrolling it? At my place of work (a spa) we have a large roll of plastic, perforated into sheets that are used in some treatments. Every time a sheet is unrolled and torn off, the person doing so gets a good shock from the static electricity. Is there any way to prevent these shocks?

The plastic is wrapped around a cardboard tube, which is strung on a wooden dowel. The dowel sits into a painted metal frame which is mounted on a wood trim piece in the staff room. It's high up, so the girls stand on a metal-framed stepladder with plastic steps and with plastic feet on one side, a metal bar on the other. The ladder sits on the carpeted floor while it's used. We're up in the mountains at about 9000 feet above sea level, a very dry climate, which seems to contribute, especially during cold weather.

The whole apparatus is pretty close to plumbing and electrical boxes, conduits etc, if that helps for grounding points.

cell phone static and home stereos

minicloud — Sat, 29 Mar 2008 12:17:38 -0800

Why does my cellular phone cause my home stereo speakers to make strange noises? Sometimes it happens when a call is about to come in, but mostly it just happens periodically for seemingly no reason. It sounds like strange beepy static and it happpens much more frequently now that I switched to an iPhone. Is there a way to stop this besides throwing my iPhone across the room?

How do you -really- ground yourself?

GleepGlop — Thu, 28 Feb 2008 21:11:20 -0800

Help me clear up my understanding of how to ground myself when working on my computer. I generally thought that as long as I touch something metal that can conduct a charge to the earth without being interrupted by say, my rubber shoe soles, then I was 'grounding myself'. And I figured that even if I am not in constant contact with said metal object, as long as I wasn't shuffling around on the carpet in my socks I wouldn't build up a sufficient static charge if I hadn't touched the metal object in a couple of minutes. Now I fear I may be completely off base what with talk of static discharge wrist bands that you attach to your ground plug in your electricity socket, and talk of leaving the computer plugged in to ensure that the ground is being reached through the ground plug...
I generally work on my computer on the carpet but I figure it doesnt matter because usually i will put a metal object under my foot. How does one ground oneself?

Can I really wash my hair less?

sian — Fri, 22 Feb 2008 07:34:21 -0800

Can I really wash my hair less? I'm a woman with long hair. It's fine (but there's a lot of it), it's stick straight, it's staticky and if I go a day without washing it, my scalp immediately gets unbearably itchy and flaky. Wash it in the morning, and my hair is a grease trap by the end of the day.

I read here and there that if you stop washing your hair daily, it gets back its natural oils and for straight hair, might even get some natural wave, which is why I'm interested in this idea.

How long can I expect the greasy, flaky, itchy, staticky mess to resolve if I stop shampooing? How often should I do it? What products (cheaper the better, please) would best help? Also, is this even a feasible idea for someone with dandruff?

How do I stop the noise from my motherboard coming through my speakers?

Grod — Sat, 16 Feb 2008 19:27:33 -0800

I have an old bose acoustic wave radio serving as my PC speakers. Powered but not connected to the computer the speakers produce a gentle hissing. When plugged in (via a 3.5mm to RCA cable) I hear noisy static -- not pure white noise, far more annoying -- and an intermittent whine that changes pitch depending on what's going on in the computer. For example, if the processor is under greater than 30% load all the noises go away. This does not happen with headphones so I think it is some combination of noise in the computer circuits and the amp built into the radio. My question is how do I make it stop? This is my only audio equipment and doubles as my alarm clock. Most of the time I can ignore the sound but sometimes it gets inside my skull and drives me nuts. There are all sorts of odd sounds I can't describe, when there are lots of read/writes to the ram I can tell by the sound. Very irritating. (Sometimes, like now, I end up with ringing in my ears which may or may not be related. Testing that is another reason I want to eliminate these noises.)

I thought this was supposed to be static-free

Ms. Saint — Thu, 04 Oct 2007 16:17:39 -0800

What factors affect my XM radio's reception? I've had my XM radio in my car for about 10 months now. Most of the time, I only listen to it when driving to and from work (about three miles each way). This means that I'm usually listening to it at the exact same place I was the day before, and the day before that, and so on.

The thing is, sometimes it's staticy and sometimes it's not. There is an underpass that I go under every day--a few weeks ago, there were three days where the sound would short out for a split second when I went under it. Since then, however, the radio has sounded perfectly fine at that part of my route. Similarly, there is an intersection where, sometimes, the static gets so bad that I can hardly hear the music. Other times, there's no static there at all. Most of the time, at that intersection, the static is noticeable but not very loud. I have never noticed any important differences at these locations (and others where the radio behaves similarly) on the different days (though I'll admit I don't know what to look for).

So, my question is, what the heck could be causing these differences? Is it something about the FM frequency I'm using (even though I have tried several different frequencies with the same result)? Does it have to do with the receiver? Something else? Is there anything I can do to stop it?

I'll admit I don't know much about the technology, so sorry if I'm naive in some stupid way.

Craft question: Make your own Colorforms, or equivalent?

blueshammer — Thu, 12 Jul 2007 05:34:37 -0800

Can you make your own Colorforms? I need to assess some different ways of affixing small things onto large things and then easily removing them. I'm prototyping a board game in which you acquire properties and then make improvements to those properties. Some of the improvements are quite specific. The properties are represented by oversized cards with blank spaces that can receive the improvements. I would like to be able to move these cards about, which precludes the most obvious solution of simply setting tokens atop the cards. Other approaches might include:

% Printing the cards on heavy cardstock/cardboard and putting sliders on the edges. Sliders are good if you want to measure discrete changes along a continuum, but in my case I think there are more options than you could comfortably fit around a card's perimeter.

% Putting the cards inside a transparent dry erase sleeve. This is probably the economical solution, but I find it somewhat inelegant. In my experience, people want to interact with pens as little as possible when playing a game.

% Printing everything on sticker paper and affixing it to, in the case of the cards, some cheap metallic surface or, in the case of the improvements, little disc magnets. I question my ability to find these metal backings (need to be of uniform size, no sharp corners, capable of being "shuffled" in one way or another).

% Colorforms or other static-cling process. With these, however, I don't see any way to avoid going to a vinyl shop and having them do the printing, which would be ridiculously expensive because it's such a small batch. (I suppose $50 for a one-color 13"x13" sheet isn't so bad, assuming everything fits on a piece that small and can all be of the same color, but I'd like a DIY-ier solution.) I suppose I could buy existing generic static-cling bits and repurpose them, but I can't think of anything like that of the appropriate, smaller-than-a-quarter size, or that would provide a solid color field that I could cut up and draw on. Is there some cheap static cling product out there I could repurpose?

Hive mind, have you got anything for me?

My ears! Make it stop!

phaded — Sat, 21 Apr 2007 21:47:30 -0800

My PC's speakers have learned a new trick: they randomly start outputting loud, constant static for long periods of time. Why are they doing this, and more importantly, how can I stop it? This is something that's just started happening sometime in the past month or two. At random times during the day (typically around midnight, but I'm generally not home during the day, and when I am, I've never heard it happen), my PC's speakers will start outputting this loud, constant static, and this will go on for a good forty-five minutes before it subsides. It doesn't matter if I have music playing or if there's nothing else coming out of them; all of a sudden, the static begins, and I can't seem to find the mute button quickly enough.

I've tried plugging different pairs of earphones into the speaker port in the back; the result is the same.

In my Googling, one thing I found that sounds like it might be the cause is poor grounding. However, it seems like that's something that would happen whenever the speakers have power. The fact that mine happens randomly leads me to believe it's something else.

Whatever the problem is, it's very aggravating, and I would love nothing more than to stop it.

How to prevent static around the PC

mkn — Thu, 12 Apr 2007 07:35:42 -0800

Static electricity fried my PC. How do I prevent it from happening again? So I recently moved into a new apartment in an old, radiator heated building. In my first few days I noticed that there I was getting a very high amount of static shocks. There's no carpeting.. It was annoying and I made a note to get a humidifier, but it wasn't that big a deal. Until last night.

Before going to bed, I went to plug in my mp3 player into the USB port on the front of my PC to charge it. I heard a zap, the computer shut down and that wonderful burning transistor aroma filled the room. The motherboard was blown.

So after I get that replaced, I'm wondering what more I can do to prevent this from happening again. A humidifier is high on the agenda now, but is there anything else? Are there any kind of USB surge protectors? Anything?

Why is my TV picture flickering when I don't use a VCR?

Pater Aletheias — Mon, 12 Feb 2007 08:54:34 -0800

Electronics filter: When I connect Dishnetwork straight to my television, the picture is flickery and unwatchable. When I run it through my old VCR first, it's fine. I know it isn't a Dishnetwork problem, because exactly the same thing happened when I had cable. What is my VCR doing that makes the signal work, and is there something else I could use in its place?

how do i eliminate static charge caused by new office chair?

donmayo — Sun, 04 Feb 2007 22:38:15 -0800

static electricity problem: Comfy new office chair (on carpet) gives me strong static charge. My metal computer desk does not like this. Help me stop getting shocked.

Is my friend an X-man?

wubbie — Fri, 19 Jan 2007 17:01:04 -0800

What's the name of the condition for people who for some reason are highly susceptible to passing on electrical current to things like computers and other electronics, leading to strange problems with said devices? I used to work with someone who had to wear a special wristband all day because she would ruin all of her computers (through normal use, NOT working inside them without grounding herself first) and now I have another friend who swears her random and truly inexplicable computer problems are due to static/electrical activity, and we want to research ways to help prevent or reduce the problem.

How did a slice of bread give me a shock?

crystaleden — Wed, 10 Jan 2007 18:35:52 -0800

I recently received a static or electric shock from a slice of bread and I am curious how this happened. I was making toast in my toaster over the other day and something odd happened. I set the timer and walked away, when the timer went off, I went to pull out the toast. I noticed the bread was not toasted, so I opened the door of the oven to see if it had warmed up at all. When I touched the bread I received a strong shock, similar to scuffing your socked feet on the carpet and touching something metal.

I was not touching anything metal at the time and it was slightly alarming. Recently we experienced issues with the breaker for certain kitchen appliances tripping, which never used to happen.

Is there any chance these things are related or may be a symptom of a larger problem...and on a basic level, how did I get a shock from bread? Is it somehow able to hold a charge?

Dryer sheet conundrum

gregoryc — Wed, 27 Dec 2006 10:04:10 -0800

How can I prevent/elminate static cling without dryer sheets? My in-laws don't use dryer sheets. I can't stand static cling. I cannot leave this house. We have most normal household items (sans dryer sheets!).

Zap

Civa — Mon, 27 Nov 2006 23:26:52 -0800

OK this might seem really silly but I'm having a static electricity problem and it's driving me insane. I don't seem to be able to go shopping anymore without getting loud painful zaps when I touch the shelving or even tins of food or anything with a foil cover, not to mention the shopping trolley. I'm sure this would be funny if it weren't so painful. It hapens when I'm driving too as soon as I step out of the car ZAP. It doesn't seem to matter what I'm wearing, if my hair is dry or wet....the weather..nothing. It's really making life a bit miserable...Any solutions?