Weekly Subject 02 - Safety and Computers

Usually to test out a power supply one will use a meter to check the voltages, but I wouldn't recommend that to a novice. Most definitely would not recommend opening up the power supply. Even unplugged, there are voltages there can could pack a wallop. (Same for the monitor). (Hey, if it smells burnt, it probably is. https://discussions.virtualdr.com/) Better to just replace it than to venture into the Land of Shock. It's worth the 40 to 60 bucks to avoid defribrillating oneself.
People will often keep upgrading like crazy; adding all sorts of peripherals, but don't think to upgrade that old power supply. So they end up running 4 to 8 IDE devices, a sound card, a vid card, a mobo, a NIC, and 512 mb of RAM on a 175 to 200 watt power supply. Go find a priest...your computer is about to die. You're overloading. Oh, it might go on for a while, but it's under a strain. Put your hand over the ps exhaust port. If it's mildly lukewarm, you may be OK; but if it's hot enough to dry your hair with, get ready for a breakdown.
(I'm just full of good news today, huh?) https://discussions.virtualdr.com/

kallikru,

My comments were addressed to some of the members giving questionable advise.

Such as:
1) zam1el, working on live machine in a puddle of water.
2) dacomputers, who does not use proper anti-static handling procedures because of improper understanding of anti-static tools. If Philgo were to use the procedure he suggested after reading dacomputer's post he would provide an excellent circuit path across his/her chest.

Other members need to be warned of the inherent dangers involved in working with electricity. If not for your own peace of mind then think of the potential liability that the website owners and advise posters may face if a member should sue after injuring himeself/herself.

In our lawsuit crazy world where people are sued for serving hot cofee (McDonalds), it pays to be protect yourself by making sure the end user understands the dangers involoved.

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Once, during Prohibition, I was forced to live for days on nothing but food and water. - W.C. Fields

i hear about kids that keep the case off . they think its cool i say its dumb, stuff could spill in it

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o4 breathalyzer is a safer lower drunk driving test in some states

so much information here . can someone make a quick outline for main points of safety?

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o4 breathalyzer is a safer lower drunk driving test in some states

I think we may need to clarify here between static and a full electrical charge when it comes to working inside the computer. The touching of the UNPLUGGED, I repeat, UNPLUGGED case chassis each time you go in is to discharge any minor static buildup, so as not to damage the mobo, cards, etc.. Any readers here should not infer that he/she is liable to get thrown to the floor by a major jolt by following that cautionary procedure. (This includes NOT wearing woolen/flannel clothing that builds up a charge and avoiding working on carpeting). The static discharge from those will not be enough to kill; it WILL "kill" the components though.

The two main high voltage areas, even if unplugged, are the INSIDES of the power supply and the monitor. Novices should avoid going in those--leave it to the techs. (Wrist strap? Actually, wearing a wrist strap while working inside a monitor is the very WORST thing you could do...you're inviting catastrophe). And again; best policy: never, never, never stick your hand inside a case when it's plugged in. The power switch may not be on, but there's power being fed into there. Not only do you stand a chance of getting a nasty shock, but you could get your finger sawed pretty good by a fan. Observe to see if everything's working, etc., then if not, unplug first, then poke around. With a little bit of caution and common sense, upgrading/exchanging parts is quite a simple procedure.

Just didn't want any of the readers getting too paranoic about upgrading/building their own systems. https://discussions.virtualdr.com/ s_brune makes a good point: be careful when giving advice that could involve potential danger. Explain yourself as thoroughly as you can. Just because something worked or turned out OK for you doesn't make it safe or "right" for others.
A lot of drunk drivers that were involved in fatal accidents had been "driving like that
for years" and "never had a problem before".
https://discussions.virtualdr.com/

It is important that people know about their equipment especially if they want to work on it. And any time the case is opened there are hazards. This is certainly not to scare anyone but to make you aware of the dangers. We do things everyday that have risks. Driving is a risk, so is eating, taking medicine, using power tools, chainsaws, etc.
There are many more, but when you talk about safety you are learning how to handle job tasks.

We want to make people aware of what is involved working on computers. Personally I enjoy this, but those that never have done it just where do they start to learn. All of us answering a question are trying to help someone else.

Now that you have seen that a power supply deserves respect, we have seen comments on the forums about changing out cards. Say, a video card needs changing for some reason. How does a person do this and what should he/she be aware of here?


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Theres far more danger inside a computer case than electricity.

How many times have you cut your fingers on those stupid metal plates that you have to remove to get the CDRom in.

And worst of all who has upset their spouse by laying the case on its side and ending up scratching a piece of furniture, now thats danger.

The owners manual to my home computer says
when opening the computer case,
to unplug the computer and press the power
button. Does this discharge those capacitors
then? Then all I'd need to worry about would
be the static electricity damaging components
rather than personal injury. Is this always
true, or is this some sort of superior
circuit design?

s_brune,
...and my comments were addressed to no one in particular. I just felt that your comments could be mis-interpreted as a general "keep out".

I'm sure we don't disagree (very much) in principal. People should not mess with things they don't understand, but the whole point here is that we try to give an understanding of these things - as you say yourself: "...making sure the end user understands the dangers involoved" - I agree fully. If some guys like to play with their lives then that's their problem - personally I don't.

But let's not overplay these dangers. I know there are people/lawyers living off lawsuits around the world (fortunately not in this country, where the laws assume a certain amount of personal responsibility - called "bonus pater familia"...sorry, I couldn't resist this little sort of off-topic), but people shouldn't let that stop them from pursuing a great hobby. As long a the rules of play are followed, why not play ball...?

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Karl, Denmark
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"..and may The Force be with you too..."

wheat1km: yes, that procedure is to "clear" any residual voltage. (But it's still not a good idea to poke around the insides of the power supply). But you can work on the mobo, RAM, hard drives, etc. as long as the system's unplugged (using the chassis touch or wrist strap). If you use the former, make sure you do it each time you go into the case and/or before handling a component.

Philgo, LOL That was funny. About time someone said something to break things up a bit. But as much as we are in "fear" of our spouses make sure your work is safe when you leave it for you families sake. There has not been anything said about making your famiy aware not to be poking around when you are not there. How do you do this? With children the first thing they will do after you say don't do something is exactly what you said not to do. So perhaps show them. Is this an issue?

BTW you contributers are doing a nice job and we are getting many views here. Let's see wasn't it JTDoom that was talkin about doing summaries. Correct me if I'm wrong on that. zorroonecrow was asking about summarizing because of the amount of information presented. This is something to think about. Where do you say this is just enough or this is to much. I would rather see to much than not enough and we can save these threads and re read later to get more out of it.

I will say this, there is information here I have never seen before. Of course There's alot of things I've never seen. https://discussions.virtualdr.com/



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Quote:

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Originally posted by wheat1km:
The owners manual to my home computer says
when opening the computer case,
to unplug the computer and press the power
button. Does this discharge those capacitors
then? Then all I'd need to worry about would
be the static electricity damaging components
rather than personal injury. Is this always
true, or is this some sort of superior
circuit design?

---

No, Wheat, that does not discharge those capacitors. It only ensures that no more power is fed into those capacitors. If you wan't to be completely safe from what hides inside the capacitors then your have to unplug the ATX/AT connector from the mainboard too (the wide one).

The power supply (PS or PSU) contains a transformer, though, that transforms your 120/230 Volts to 12, 5 or 3.3 volts, and I've so far not heard of anyone being electrocuted by touching the unplugged mainboard. But always be wary when working with electricity.


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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 06-04-2001).]

My experience with computer case is that the outside is smooth and free of obtructions that will cut you, but be careful on the inside while you work as the edges of the metal can be very jagged. And if it catches you hand or arm it will more than likely cut you.
Just take it slow and easy and it is very simple to work on computers. But, if you have any doubt in you mind, I for one will not blame anybody for having it done.


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darn shifts

to change a light-bulb in a fixture, make sure the power is OFF. Not just the switch you use to flip it on/off.
You go kill the circuit at the fusebox.
why, you don't wanna get thrown off a ladder/chair/table/stepup.
hell, you don't wanna fall. period.
I tell you that it's no fun to touch the live end of a single 230V (and 110V kan KILL too)

in our dialect, we call that other thing a differential switch. Its mandatory.
the overall 300 milliamp differential, protecting ALL circuits comes from the main trip fuse.
A 30 milliAmpere differential is installed behind it for all appareil around kitchen, bathroom and the washing machine

if you are working alone, and know you gonne be alone until you finished, THEN there is no real need to put a poster up.
But when you are not alone in the house, you better make sure everybody knows you gonna switch some circuit off, and make sure it STAYS off.
best way is to pull the fuses out.
when you have them automats, switch it off, tell everybody, and rely on the switched powerstrip YOU use and can keep an EYE on.
some moron WILL switch the automat back on.
I believe it's called Murphy's LAW

GET that switched powerstrip.
you can switch off and stay grounded.

and yes, POWER OFF all peripherals, and disconnect every peripheral from case when you need do work inside the case

when you need remove cutouts, don’t bend metal with your bare hands.
Use pliers.
Hell, I use fine leather gloves AND pliers
Blood aint good for the mainboard.
Bleeding aint good for the human

One of these days Zam1el will have to change name
It Could become ZAPPED1el 

Listen, there is no one-up-ism involved when working on ‘tricity.
You get either killed or fired when you work unsafe. Think it over.



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You help someone with a similar problem if you tell us what worked.
When you do, please post solution in the original thread?
Kind regards, Jaak

jaak
if you are in the mains and to be safe lock it so no one can apply murphy's law to you. Might even want to put A second lock on it also.

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