Jump to content


 


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.


Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.

Photo

Electrified Case?


  • Please log in to reply
9 replies to this topic

#1 Gothmog

Gothmog

  • Members
  • 172 posts
  • OFFLINE
  •  
  • Local time:10:54 PM

Posted 13 July 2006 - 10:51 PM

I was just unpluging my speakers to plug in my headphones on the back of my computer and I'm pretty sure I felt a tingly low voltage shock when my finger touched the (unused) onboard VGA port. Just to be sure I stuck my finger back on the area and felt the sensation again (like an ant is crawling on you is the best way I can describe it). Do you think this is normal, something imaginary or pretty serious that I should fix right away? I don't think its normal for the back plate or even a port to be hot!

BC AdBot (Login to Remove)

 


#2 J_pyro_C

J_pyro_C

  • Members
  • 131 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Newalla, OK
  • Local time:08:54 PM

Posted 13 July 2006 - 11:06 PM

i really have no idea if this is normal or not but i have had a couple of computers that did that too but everything worked for a long time afterwords but i would still be caucious and maybe someone else can help clear this up a little for us.


#3 Gothmog

Gothmog
  • Topic Starter

  • Members
  • 172 posts
  • OFFLINE
  •  
  • Local time:10:54 PM

Posted 13 July 2006 - 11:30 PM

at least I'm not alone. Did you ever have a card or drive fry or fail unexpectedly (not that we ever expect them to)?

#4 J_pyro_C

J_pyro_C

  • Members
  • 131 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Newalla, OK
  • Local time:08:54 PM

Posted 14 July 2006 - 03:07 AM

yes that has happened to me aswell.once when i was on the computer i was playing a game,im not sure but i think it was counter-strike,and all of a sudden the comp shut down and i tried to turn it back on and it kept sayin theres no operating system and it turns out that somehow when i was playing the game the harddrive fried.and by the way i hope we NEVER expect for drives to fail or fry lol.(thats just wrong,poor computers)

Edited by J_pyro_C, 14 July 2006 - 03:09 AM.



#5 stevealmighty

stevealmighty

    Bleepin' WormBreath


  • Members
  • 2,629 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Upstate NY
  • Local time:09:54 PM

Posted 14 July 2006 - 07:53 AM

If it's a constant voltage that you're feeling, then there is a problem and something needs to be replaced....it's just a matter of finding out what.

If it's just a "static shock" from standing on carpet, or a cloth/plastic chair, then an anti static floor mat should do the trick.

First thing I would do is to double check all the connections inside your machine. Make sure that everthing is plugged in tightly and is seated correctly. Make sure that any extra wires you have that are unused from your power supply are covered and not touching anything else. I've fried a power supply by accidently letting a lead touch the case. It was an expensive mistake. Now I put electrical tape over any unused leads (wires/plugs) coming off the psu.

Also, you might want to make sure that you're plugged into an outlet that has a ground on it. Some older outletts don't have grounds, but you can buy an adapter for a few bucks to give you a ground. If possible, I'd replace the power cord to your psu, too. I know it's a far shot, but I've had it happen to me ("faulty" cord). I kept getting shocked everytime I touched my case, then once I fried my sound card because of a static shock. I replaced the cord to my psu and (knock on wood) haven't been shocked since.

Worst case scenario is that you'll have to replace your power supply (psu) or another component (mobo?). Let's hope you don't have to go that far.

Hope this helps!
War produces veterans, wounded both physically and mentally. They have sacrificed for us.....and it is now our job to help these veterans, as they have already helped us in ways we will never know, in ways that we cannot fathom, and in ways that we take granted every day.
Posted Image

#6 just me

just me

  • Members
  • 126 posts
  • OFFLINE
  •  
  • Local time:10:54 PM

Posted 14 July 2006 - 09:17 AM

Just a word of caution. The jack for the speakers is line-out. Headphone impedance is generally about 32 ohms and line-out impedance is about 1000 ohms.

You should not plug headphones into the line-out jack and never plug line-out devices into a headphone jack (i.e. never plug the speakers into the headphone jack or plug the line-in of a stereo to the headphone jack).

#7 stevealmighty

stevealmighty

    Bleepin' WormBreath


  • Members
  • 2,629 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Upstate NY
  • Local time:09:54 PM

Posted 14 July 2006 - 09:47 AM

Just a word of caution. The jack for the speakers is line-out. Headphone impedance is generally about 32 ohms and line-out impedance is about 1000 ohms.

You should not plug headphones into the line-out jack and never plug line-out devices into a headphone jack (i.e. never plug the speakers into the headphone jack or plug the line-in of a stereo to the headphone jack).



Very good point just me. I was unaware that there was such a difference in the ohm rating between the 2 jacks. Do you think this is what was causing the "tingling" sensation?
War produces veterans, wounded both physically and mentally. They have sacrificed for us.....and it is now our job to help these veterans, as they have already helped us in ways we will never know, in ways that we cannot fathom, and in ways that we take granted every day.
Posted Image

#8 just me

just me

  • Members
  • 126 posts
  • OFFLINE
  •  
  • Local time:10:54 PM

Posted 14 July 2006 - 04:47 PM

stevealmighty:

Do you think this is what was causing the "tingling" sensation?

No I don't think that it is the cause of the problem, particularly since Gothmog indicated that they thought that the "... low voltage shock" was from "... the (unused) onboard VGA port."

Actually my comment was related to what Gothmog was doing when they discovered the problem and not necessarily related to the actual cause of the problem that was discovered while doing it (i.e. "Electrified Case? " - "I'm pretty sure I felt a tingly low voltage shock when my finger touched the (unused) onboard VGA port.").

I was just trying to point out to anyone who reads this thread that although both the line-out jacks and headphone jacks accept 1/8" (3.5 mm) plugs they are not necessarily interchangeable.

Edited by just me, 14 July 2006 - 04:48 PM.


#9 Gothmog

Gothmog
  • Topic Starter

  • Members
  • 172 posts
  • OFFLINE
  •  
  • Local time:10:54 PM

Posted 16 July 2006 - 01:47 AM

interesting, just me, I may have been doing a bad thing for years. My sound is onboard also and there are three 3.5 mm jacks. One is for output, one for mic and another(line in i guess). I have no where else to plug in a headphone b/c I have low end desktop speakers without a built in jack and none on the front of the case (cause the mobo is lowend too).

what would be the problem with the increased resistance of a line out connected to a pair of headphones? I am currently using a set of RCA wireless phones, mostly cause my reguar ones have short cords.

Whatever current there might have been going through the mobo connectors is gone at this time. I'll see if I can chase the problem down if it comes back.

#10 just me

just me

  • Members
  • 126 posts
  • OFFLINE
  •  
  • Local time:10:54 PM

Posted 17 July 2006 - 07:46 AM

The best way that I can think of to explain this is:
  • Question:
    • Can you use the "line-out" of a computer with intergraded sound or a PCI card to drive headphones directly?
  • Answer:
    • Maybe.
The "line-out" output of intergraded sound or a PCI card in a PC is essentially equivalent to the "line-out" of a preamplifier in a stereo system. You don't hook either the speakers or headphones to the "line-out" (usually a pair RCA jacks) of a stereo system. You hook the speakers up to the connectors for the speakers (in some cases RCA jacks but usually bare wire connectors) of the amplifier. You plug the headphones into the headphone jack (usually a 1/4" jack) of the amplifier.

Along comes a PC and miniaturization. The "line-out" of intergraded sound or a PCI card is a 1/8" (3.5 mm) stereo jack (rather than RCA jacks). The speakers designed to be plugged into "line-out" of a computer are not normal speakers, they are amplified speakers which boost (amplify) the signal ("line-out") from the PC to produce sound.

Similarly, the "line-out" output of a PC is not designed to drive headphones. The "line-out" generally has very high output impedance and may not have enough current capability to drive headphones adequately. A well designed circuit will probably work without damage, however, there is a risk that the headphones will draw too much current and damage the circuitry.

It would be better to run the "line-out" from the computer to the "line-in" of an amplifier and use the headphone jack on the amplifier.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users