Hmmmmmm....so to get hit with 5,000 volts DC or AC (with the amperage say...oh...around 5)? Decisions, decisions.... https://discussions.virtualdr.com/
Think I'll sleep on it...Nite!
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Hmmmmmm....so to get hit with 5,000 volts DC or AC (with the amperage say...oh...around 5)? Decisions, decisions.... https://discussions.virtualdr.com/
Think I'll sleep on it...Nite!
EDIT: Some of the following post are not to scare people but are Technical in nature to try and figure if the equipment in various countries are the same with different names is all. And it turns out to be true. All toward our safty.
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SMILE
and post back
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[This message has been edited by Train (edited 06-03-2001).]
In my 35 years as an electronic tech., I've had the opportunity to be knocked on my rear by all sorts of excited electrons; AC, DC, RF, microwave, high Amp and low. I've also had the 3/4 million volts from a DeGraff generator pass through me and light a florescent bulb without harm (lots of volts, no amps).
When you hook yourself up to an antistatic strap or grab the chassis, you create an excellent path for electricity, right throutgh your body. While this protects the delecate electronic parts from being harmed by a atatic discharge, it places you directly in harms way. What we techs are taught to avoid is giving the electricity a path through either your heart or your brain bucket.
Electricity follows the shortest path so if the grounding strap is attached to the arm you are doing the fingerpokin' with the brunt of the shock is restricted to your arm. If you ground one hand and poke around with the other the path goes right across your chest and you put your ticker right in the line of fire.
I have NEVER used a grounding strap, and I handle delecate computer components all the time. I use one simple rule. TOUCH THE CHASSIS FIRST AND LAST. It's safe for me and the components.
DA
I always wear a wrist strap connected to earth via a mains socket (turned off of course), this is something I hate doing. If I was to not bother in future and I was to keep my arm touching the case will the power supply have to be plugged in so it is connected to Earth, or is it simply enough for me and my machines case just to be in contact?
It is best to have an earth ground, but the important thing is to have the components and you at the SAME potential so you don't jump a spark when you touch the component. Momentarily touching the chassis usually accomplishes this quite well.
If you find that you get frequent shocks from doorknobs and such around your house or office, spray the carpet with static guard and insulate yourself from the carpet with a rubber mat or rubber-soled shoes in the work area.
DA
dacomputers, as I usually work in a carpetted room, its probably best that I continue with my strap, thanks
'morning beauties (once you get up),
I've worked the insidings of computers at home for over 15 years now. In fact, that is what got me hooked on engineering - that and NC/CNC machines...
I've never owned a wrist strap, but I've always made a point of discharging myself by touching the chassis first, before I touch anything inside the machine. Never had anything destroyed by static discharge.
I've had one experience,though, where I thought I had destroyed an IBM TP760 completely - but no harm came to the TP, luckily.
I had switched off the machine (placed in a dock) and was about to draw a phono cable from the speaker-outlets in the room (radio switched off to stand by) to the audio line-in on the computer, to record some of my old vinyl records on CDs.
Thinking this was an external connector (as it is..) I didn't pull the plug. I soon realized my mistake: Before I could stick the phono plug into the line-in socket, a small spark jumped between the two and all lights and everything else went dark - the house was without any power at all.
I went to look at the fuseboard and found that the HFI-relay (don't know the english name - may be the same? Works fx. against what we call "creeping currents") had kicked in and cut all power to the house. Once I'd pulled the plug I could reset the HFI-relay and power came back on.
Thinking a bit about it I asked myself how the current had gotten there? I then realized what my mistake was: The speaker-outlets in the room are connected to a "link" (Beo-link - B & O HiFi...if anyone knows them) that transmits commands from a remote contr. to the system placed in another room in the house - gives you music in every room of the house via these links once you install speakers.
Although the radio system had been put into stand-by, this link was still very much alive and powered (by the radio). Cutting off the speakers (at a switchbox) cut the power and work could be resumed - to my relief noothing had happened to the PC.
Never underestimate electricity - neither the strong nor the weak currents. They can be equaly destructive to sensitive equipment.
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Karl, Denmark
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"..and may The Force be with you too..."
[This message has been edited by kallikru (edited 06-02-2001).]
[This message has been edited by kallikru (edited 06-02-2001).]
Good Morning All, Looks like a 24/7 operation around here but besides not like being shocked this ole body still needs sleep. https://discussions.virtualdr.com/
Thanks to all of you for your inputs.
Let's see two questions were asked and not answered, so to rephrase:
How do I clean my monitor glass safely?
I want to change a stick of RAM so memory will operate faster. This means going into the computer - opening up the case. How is this accomplished safely both for myself and the computer?
And while you experts think about how to answer these two questions there are a couple of Honey Dos to be accomplished. https://discussions.virtualdr.com/
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1) I clean my monitor on or off all the time. Doesn't seem to make a difference.
2) Just replaced the RAM in my machine last night.
Power off.
Unplug everything
Open the case and touch bare metal part of case while standing on anti static mat wearing rubber sole shoes.
Don't use power tool such as screwdrivers, power saws, grinders, etc. inside the case.
Carefully replace the sticks while not touching other things when possible.
Replace the cover.
Plug everything back in.
Hit the power button.
Hold your breath.
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Si Hoc Legere Scis Nimium Eruditionis Habes.
(translation: If you can read this you're
overeducated)
[This message has been edited by Trish-A (edited 06-02-2001).]
One suggestion on cleaning your monitor. If you use something water based such as "windex"? Use paper towels rather than cloth.Cloth may be/contain nylon,dacron or other synthetics conducive to static. Also, spray the cleaner on the towel,"not" directly on the screen. If your not quick enough, it could leak inside at screen bottom. Use alcohol to clean the cabinet using same application method as above.
Most carpeting nowadays is synthetic and can generate a healthy static charge. That's why, not having a work room available in my Apt. i always work on my equipment in the kitchen.(staying away from water sources of course) https://discussions.virtualdr.com/ Linoleum type floor coverings are also synthetics, but don't give you the "combing the hair" type of static buildup that carpeting can..
Also, i ALWAYS power completely down and unplug before "going in" to the box. Good idea to leave it sit for an hour or so before opening things up. Gives those nasty capacitors time to discharge.
Good rule of thumb for "anyone",,,Think, before you touch!! (ain't it fun tho'? https://discussions.virtualdr.com/ )
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When your through learning,,,your through.
I'm an electrician, and here in the UK we have what is probably the highest electrical safety standards in the world, so I guess that qualifies me to say a few words about electrical safety. One of the very first things drummed into us at college is: "THERE IS NO SUCH THING AS A SAFE VOLTAGE". Having said that, when we design electrical systems over here we have to make sure that under no fault conditions can the voltage on exposed metalwork rise above 50v (except on construction sites and agricultural installations when it has to be >25v). You can read into that what you will.
As said above, it's the current that kills, keep it below 50mA and you'll be as safe as houses, you can ensure you keep below this level by inserting a 1 megohm resistor in your wriststrap, that way you get the best of both worlds, you protect the chips and yourself.
There is no difference between AC & DC as far as safety is concerned.
Be very careful inside monitors, there are very voltages inside. I happily mess about with 415v 3-phase systems all the time, but I don't like going inside a monitor or TV!
One of the best investments you'll ever make, is to have a Residual Current Device (RCD) installed in your homes (they may be called something else outside the UK). Correctly installed and rated they'll trip long before you get anywhere near a lethal current, and if you've got pets that like to chew through power cords then they are a must.
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Nick.
Just got back. Hey, you all posted good how to "stuff" from your personal experience. This is great. I can picture in my mind what you are saying. You do not find this information in any text books that I know of. This is the type on information that will help the new comers and save them alot of time wondering about.
Now, should we expand on replacing a stick of RAM? The actual how to. As a person opens up a case can you cut yourself on anything for example? Anything else that you would need to watch out for?
Trish-A gave a very good comprehensive list. Should this have more detail since we're targeting people just starting out?
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Hey SSparks,
I think your RCD device sounds like the HFI-relay I mentioned. HFI is mandatory here in DK. It's located at the fuseboard and requires a routinely one-time-a-year activation to ensure it's working properly. It will some times cut the power even before the fuses blow - sounds familiar?
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Karl, Denmark
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"..and may The Force be with you too..."
1. I believe the "RCD" and "HFI" are the same and around here I think they are called "EFI" for electrical fault interrup(sp?).
2. As far as cleaning moniters, it depends on what kind of moniters. Glass faced, TFT or LCD are different. At work we never use windex as it builds up static charge and attracts more dust. TFT's have special cleaning pads to ensure you do not scratch the surface.
3. I never clean any of them with power on. Been zapped to many times on glass faced moniters and old TV's. Also easier to see finger prints.
4. In school there were jokes about AC/DC shocks and being able to tell them apart by rather your arm flapped in sync with AC or was sraight from DC. Don't know about the AC part, but while test benching a counter radar box the intermediate power supply put 1500 vdc across my finger tip and the probe. My arm really was straight till I bounced off the roll around tool box behind me. Then all I could smell was burnt flesh. My finger looked like I had laid a hot soldering iron on it. https://discussions.virtualdr.com/
https://discussions.virtualdr.com/ Opovet https://discussions.virtualdr.com/
ps: now I try to limit my work to 12 vdc or less. https://discussions.virtualdr.com/
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I know it is true because I read it on the internet from a VirtualDr link!!
GFI/GFCI I do believe this is what you folks are refering to. If not link in a photo if possible.
Now the code I referenced earlier covers the outside of the case and to a extent the inside as well.
But, Some things you can find inside.
Sharp edges that cut.
Voltages that can hurt or harm you.
Just to name a couple.
And if you use the wrist strap, make sure the resistor is in there and wear it on the arm that you are using and "Keep the other one in your pocket" as I was instructed.
Before replacing RAM it pays to take a look inside your computer so that you know what you are getting into.
This is in reference to the fact that I have found the ram slots behind the powersupply and some research told me that the motherboard was mounted to a removable board and where the screws where that held it in place. So, I wound up almost totally dismantalling the case to put the ram in. It was a straight forward job to put the ram in. Just lined up the slots in the ram to the slots in the motherboard and using even pressure on both ends of the ram pushed it in and the keepers on both ends rolled up and locked into place.
Then on others it has taken longer to shutdown the computer and unhook everything than it did to open the case and insert the ram.
Yes, some countries have better electrical codes than we do in the US. But we use a 120V base instead of 240V in our homes. At work, now that is different .
Will see if I can find a GFI graphic.
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SMILE
and post back
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