Avoiding Static electricty

A friend of mine bought a new graphics card for his computer and he also
got a high end power supply , I told him to contact me when possible so
i can go to his place and install the new upgrades
I dont wanna end up messing it up he is low on budget so i would like to
know
whats the best way to discharge static electricty before opening the
case and working in it

PcGAmeR22;1341926 Wrote:
A friend of mine bought a new graphics card for his computer and he also
got a high end power supply , I told him to contact me when possible so
i can go to his place and install the new upgrades
I dont wanna end up messing it up he is low on budget so i would like to
know
whats the best way to discharge static electricty before opening the
case and working in it

Use an ESD Wrist Strap such as--
http://www.radioshack.com/product/in...ductId=2103245

Or at the very least touch the case frame inside (unpainted metal) from
time to time while working with the PC.
Remember to avoid touching chips, contacts or pins when handling or
installing cpu, memory sticks, and expansion cards...always hold or
press from the edges.

I dont have an esd wrist strap so i,ll just keep touching the unpainted
metal
thanks mate !!

PcGAmeR22;1341938 Wrote:
I dont have an esd wrist strap so i,ll just keep touching the unpainted
metal
thanks mate !!

Needless to say, make sure the system is unplugged before opening case.

rb wrote:
PcGAmeR22;1341926 Wrote:
A friend of mine bought a new graphics card for his computer and he also
got a high end power supply , I told him to contact me when possible so
i can go to his place and install the new upgrades
I dont wanna end up messing it up he is low on budget so i would like to
know
whats the best way to discharge static electricty before opening the
case and working in it

Use an ESD Wrist Strap such as--
http://www.radioshack.com/product/in...ductId=2103245

Or at the very least touch the case frame inside (unpainted metal) from
time to time while working with the PC.
Remember to avoid touching chips, contacts or pins when handling or
installing cpu, memory sticks, and expansion cards...always hold or
press from the edges.

The desired function, is to "bring all components to a common electrostatic
potential before assembly".

That means occasionally touching the chassis, doesn't count. Once you
remove your grasp from the chassis, now the items are "charging up again".

http://en.wikipedia.org/wiki/Electrostatic_discharge

tribocharging, electrostatic induction

Even electrolytic capacitors will do that, but for different reasons. If
you take a shorting strap and discharge an electrolytic, then release the
strap, the capacitor will still have residual charge. In fact, on the old
high voltage caps, there is still a significant shock hazard if you
do it that way.

So the purpose of the ESD wrist strap, is you connect it to the chassis,
and connect it to you. The wrist strap should have around a 1 megohm
resistor in series with it. The charge on you and the chassis equalize
slowly and the potential difference is zero.

While holding the ESD bag the video card came in, you touch and hold
the inside of the bag, while at the same time withdrawing the card
from the bag. Now, you hold the faceplate of the card (as it is grounded),
and try to continuously hold that while inserting the card. The chassis
and you are at a common potential because of the wrist strap, but the
video card would only be at the same potential, for as long as you're
touching the faceplate. You may need to switch hands while inserting
the card, to maintain continuous contact.

One reason for this degree of care, is some Nvidia motherboard chipsets
in the past, ended up with "blown out" PCI Express slots. Which suggests
the electrical signals in the slot on the motherboard, are overly sensitive
to static.

Using an ESD strap, plus using some care while inserting the video
card, should lead to a successful install. You can "simulate" the
common potential thing by cheating, but it's pretty hard to maintain
contact until the install is finished.

Devices vary, in their ability to resist ESD. I've worked with MOSFETs
in a transistor can (four legs), where there are no clamp diodes, and
the device has a 30V ESD rating. ICs can have 1001 volts, 2001 volts or higher
ratings. Those are relatively robust, compared to the 30 volt parts.
USB ports are around 5-6kV of ESD rating. The very best parts, are
RS232 chips with 15kV ESD rating on the modem data pin end. RS232
chips needed those ratings, because of the large numbers of RS232
chips blown out by static. I replaced a bunch while I was working,
on things like test equipment and even on the computers we built.
(MC1488, MC1489 chips). With the newer 15kV rating, doing replacements
like that is a thing of the past.

A human can build up a reasonable level of ESD charge, to the 50kV
level. That means if you're completely clueless, scuff across
the carpet and then touch the PCI Express slot on your motherboard,
it's going to be blown. Even the RS232 chips could be blown, if you
could get close enough to the pins while scuffing across the carpet.
A lot of connectors, due to the metal shell around the pins, that
provides "direct contact protection", where the discharge would
have gone right into the pin. But ESD can also do damage by induction,
which is how a lot of stuff in your house gets damaged in a
lightning storm. A conductor could be hit 100 feet from you,
and just the induced voltage in conductors within the house,
will destroy stuff. The same is true of ESD discharge on connectors,
in that, the charge may dissipate into the chassis, but not before
being induced into adjacent conductors.

This is one of the proposed failure mechanisms on ICH5. A user discharges
ESD into the metal shell of the front panel USB connector. But because
the metal shell doesn't have a good connection to metal in the chassis
(the front panel is typically made of plastic), the discharge into ground
goes down the ground wire in the USB front panel cable. But at the
same time, the ESD is induced into the adjacent D+ and D- signals,
leading to latchup failure at the ICH5. So in the computer, one of
the worst designs from an ESD defense point of view, is front
panel connectors. By seating the connectors in plastic, that's asking for
induction based failures. And is why I recommend making connections
to a PC, via the rear connectors. As everything back there has a
metal connection to the chassis. That's why the rear I/O plate
has those "springy fingers". It helps with ESD. The springy fingers
shorten the distance an ESD charge has to travel, to get to the chassis
metal.

Paul

On Wednesday, May 23, 2012 6:29:13 AM UTC-7, PcGAmeR22 wrote:
A friend of mine bought a new graphics card for his computer and he also
got a high end power supply , I told him to contact me when possible so
i can go to his place and install the new upgrades
I dont wanna end up messing it up he is low on budget so i would like to
know
whats the best way to discharge static electricty before opening the
case and working in it

An anti-static wrist strap works great but needs to be used properly. For example, assuming it's connected to the computer case, you still have to first touch the anti-static wrapping of the graphics card and should remove the card by picking it up at the rear bracket (ground). But if you set the card down outside the computer, you could zap it with static.

The closest thing to a no-brainer anti-static solution is to remove shoes and socks and work in short sleeves. Cover the whole table top with anti-static wrapping, like pink anti-static bubble wrap or anti-static foam wrap, preferrably with it dangling slightly at the front of the table, and set everything on the table before unpacking it from its antistatic wrapping. Short sleeves and having the anti-static covering dangle at the front make it highly likely you'll discharge your static and avoid zapping stuff.

I don't know where to get anti-static wrapping cheap, but Staples has a 2' x 30' roll of anti-static bubble wrap for $16:

http://www.staples.com/Staples-Anti-...product_657404

"PcGAmeR22" wrote in message
...

A friend of mine bought a new graphics card for his computer and he also
got a high end power supply , I told him to contact me when possible so
i can go to his place and install the new upgrades
I dont wanna end up messing it up he is low on budget so i would like to
know
whats the best way to discharge static electricty before opening the
case and working in it



I keep part of my arm on the chassis at all times.

"PcGAmeR22" wrote in message
...

A friend of mine bought a new graphics card for his computer and he also
got a high end power supply , I told him to contact me when possible so
i can go to his place and install the new upgrades
I dont wanna end up messing it up he is low on budget so i would like to
know
whats the best way to discharge static electricty before opening the
case and working in it

Leave the PC plugged in and turn off the socket at the wall to cut the
power - the whole case is then earthed and anything touching the case is
also earther. No need for anti-static straps, wrist things or anything
clever.

"Thip" wrote in message
...

"PcGAmeR22" wrote in message
...

A friend of mine bought a new graphics card for his computer and he also
got a high end power supply , I told him to contact me when possible so
i can go to his place and install the new upgrades
I dont wanna end up messing it up he is low on budget so i would like to
know
whats the best way to discharge static electricty before opening the
case and working in it


I keep part of my arm on the chassis at all times.

That's fine if the chasis is earthed!

On Saturday, May 26, 2012 3:20:26 PM UTC-7, GT wrote:

Leave the PC plugged in and turn off the socket at the wall to cut the
power - the whole case is then earthed and anything touching the case is
also earther. No need for anti-static straps, wrist things or anything
clever.

Wrong. Really wrong and potentially dangerous.

You shouldn't leave the AC cord plugged in because a direct, low impedance connection between you and earth ground can be dangerous, as evidenced by people touching defective toasters and faucets at the same time. That's why anti-static wrist straps have a million ohms between them and their ground clips. Some electronic assembly factories make workers go through a checkpoint where they have to plug in their wrist straps, and any that measure more than about 2 megaohms or less than 1 megaohm are rejected.

It doesn't matter if the computer chassis is at earth ground or 20,000 volts higher. The only thing that matters is for everything to be at the same voltage, and your recommendation won't eliminate the need to take anti-static precautions.