device or computer acting wacky?
- could be static damage,either of the device, or of the card.
- device age: chips only work for so long, mainly due to metal migration issues or whatever. older 1990 pc motherboards with the NiCd barrel batteries typically last 10 years before they die out and need to be replaced. my old nokia 6010 cell phone went wacky after 6 years of use,so I replaced the battery. this fixed it only temporarily. once a cell phone goes nuts, time to upgrade phones - it's not just the battery that's gone, it's the phone too! my previous phone was starting to drop calls randomly on 1st ring.
about ESD - Electro-Static Discharge
- office cubicle walls which are filled with Styrofoam (notice how Styrofoam sticks to you): up to 18kV
- getting up out of an office chair (this wasn't done at the time of my class. I would test it, but ESD meters are expensive)
- static you can feel: 6kV-10kV
- rayon, nylon, polyester pants
- people hair against certain materials like rubber or the above
- friction (walking across a carpet)
- a silk tie: 300V
What really causes static (Electro-Static Discharge)?
static is generated when two surfaces are separated. friction is one example of this (think: rub balloon on hair). please note that TTL chip voltage is 5V, some computer chip voltages are 3V or less.
ESD usually doesn't carry a lot of current. if it did, it would be deadly, like car batteries, 440VAC, and lightning.
how do you protect against ESD?
- being gentle and ginger does not shield it,as much as we would like to hope it does.
- I have also noticed that my office chair is a real culprit for generating huge amounts of static when I get up. so I have learned to put away objects from me before I get up out of the chair (well,usually I am successful, not perfect).
- the fewer times you do ESD events, the less damage you cause to the system.
- buy a motherboard which has ESD protection on ports. makes me feel awful when the static routes through my headphones into the speakers andinto my pc audio port. I hope mobo manufacturers take thought to put MOVs on those or something to get rid of the static. gas discharge tubes work even better and clamp harder.
- cement floors don't have much chance of generating static.
- use static shielding bags for your cards, parts, anything with electronics being shipped. pink poly and blue poly is NOT anti-static, it merely doesn't generate static - big difference! static shielding bags workby building a Faraday Cage around the part. this means the part must have the bag fully closed for it to work. here is a list of types of static shielding bags in order of expensive+higher quality first:
- copper (very expensive and hard to find, brittle)
- nickel (flexible, works great)
- plastic with black lines
- anti-static wrist-strap with alligator clip to exposed metal part of case, or connected to ground clip on antistatic workstation/mat when handling or installing parts,or touch the case you are installing into. I should think at the very least you and the target and the part should be at the same Voltage Potential.
- antistatic heel straps for grounded floors
- antistatic workstation/mat with ground clips
- be aware of separating surfaces or friction. think of a way you can avoid separating surfaces too many times if possible.
you probably won't need to go overboard buying things (it can get mighty expensive) unless you are running a computer room or clean room. you can probably get by with a wrist strap and MAYBE some static shielding bags once in a while. a lot of this stuff comes in handy for Computer Repair Professionals.
ESD protection for headphone jacks and microphone jacks
this applies to devices where you could plug in cans (headphones) or mics like:
- tv headphone jacks
- mp3 players
- pc speakers
- usb/firewire/thunderbolt/etc audio interfaces
ESD protection for the port can be had with a MOV or varistor. they are inexpensive (as little as $0.16), and to make an inline ESD protection cable, you would need to