Computer Maintenance

1. Computer Maintenance Safety/Electrostatic Discharge (ESD)

2. Enabling Objectives • What Is Electrostatic Discharge (ESD)? • Why is ESD important? • ESD Damage • Preventing ESD Damage • ESD Workstation Components • ESD Wristband or Ankle Strap • ESD Floor or Table Mat • ESD Garments • ESD Gloves or Finger Covering • Increasing Humidity • Anti-static Bags IT: Computer Maintenance - Safety & Electrostatic Discharge

3. What Is Electrostatic Discharge (ESD)? Electrostatic Discharge (ESD) • When two objects rub together they create friction. • A by-product of friction is heat. • The result of the increased molecular activity brought about by electrons moving back and forth between the two surfaces. • Our bodies are constantly in motion. When we move against another material, like carpet, we create friction. • This results in rapid movement of electrons, some of which remain in our bodies. • This exchange of electrons builds up a charge within our bodies IT: Computer Maintenance - Safety & Electrostatic Discharge

4. What Is Electrostatic Discharge (ESD)? (cont.) Electrostatic Discharge (ESD) • Built-up electrons inside us are seeking an outlet: • A way to flow through us to another electrically conductive material that isn’t quite as charged up as we are • Such as a doorknob • When we make contact with another electrically conductive material, the electrons jump from our bodies to the other material. • So static electricity is the buildup of an electrical charge within an object, such as a person, the discharge of which is in the form of electricity. IT: Computer Maintenance - Safety & Electrostatic Discharge

5. Why is ESD important? • Our bodies constantly generate and release static electricity. • Almost every time we touch something, we discharge some amount of static electricity. • While you work on a computer, you can discharge static electricity to the components of the system just by touching them. • The human body can only feel an electrostatic discharge of 3000 volts OR MORE. • Less than 100 volts can damage or destroy the delicate circuitry found in computers. IT: Computer Maintenance - Safety & Electrostatic Discharge

6. ESD Damage • Discharge of high levels of electricity into wires and components not designed to accept such levels will result in damage. • Damage is not always immediately apparent. • Partial damage can result in intermittent errors in the computer because some pulses still flow properly while others don’t. • Users will complain of errors and problems that are not always duplicable. IT: Computer Maintenance - Safety & Electrostatic Discharge

7. Preventing ESD Damage • Ensure that any electrostatic buildup in your body is discharged immediately to the ground. • You must provide a direct ground path from your body. • Use special electrostatic dissipative products. • They slow the transference of electrostatic energy, allowing it to dissipate before damaging components. IT: Computer Maintenance - Safety & Electrostatic Discharge

8. Preventing ESD Damage (cont.) • As a computer technician it is your responsibility to ensure you don’t cause damage to the systems you are servicing. • Create an ESD workstation or environment to reduce ESD damage. • A good ESD workstation should incorporate the components shown on the next slide. IT: Computer Maintenance - Safety & Electrostatic Discharge

9. ESD Workstation Components • ESD wristband or ankle strap • ESD floor or table mats • ESD garments • ESD gloves or finger coverings • Increased humidity • The presence of moisture allows electrons to better discharge safely into the air • Anti-static bags IT: Computer Maintenance - Safety & Electrostatic Discharge

10. ESD Wristband or Ankle Strap ESD wristband or ankle strap • Attached to the wrist with a wire leading to a metal clip attached to the grounded object • Can be grounded to various items: • ESD mat • ESD floor mat • Metal table or chair leg • Removed computer case • Separated from any components you might touch IT: Computer Maintenance - Safety & Electrostatic Discharge

11. ESD Floor or Table Mat ESD Floor or Table Mat • A floor mat placed where you stand • The underside has contacts that provide an outlet for ESD to the ground beneath • The floor and underneath the mat should be kept free of dirt and debris • The table mat is placed on your work surface • Provides a route to ground through: • Contacts underneath to metal table or • The grounding strap that runs from the mat to a grounding source IT: Computer Maintenance - Safety & Electrostatic Discharge

12. ESD Garments ESD Garments • Worn over your clothing and provide a ground wire that can be attached to an ESD floor or table mat • Made of a static dissipative material that slows ESD to give it time to discharge to the ground through the ground wire IT: Computer Maintenance - Safety & Electrostatic Discharge

13. ESD Gloves or Finger Covering ESD Gloves or Finger Covering • Worn on the hands or fingers that will come into contact with sensitive components. • Can be made of one of the following materials: • Vinyl • Good for anti-ESD work • Special substances to dissipate or prevent ESD transference. IT: Computer Maintenance - Safety & Electrostatic Discharge

14. Increasing Humidity • ESD buildup is greatly reduced in a humid environment. • As the presence of moisture in the air is increased, electrons are better able to discharge safely into the air instead of onto another object. • Using a humidifier to increase the air moisture in your work area can greatly reduce ESD buildup. • Too much humidity can cause condensation that can damage components. IT: Computer Maintenance - Safety & Electrostatic Discharge

15. Increasing Humidity The Difference in ESD Generation Based on Relative Humidity (RH) IT: Computer Maintenance - Safety & Electrostatic Discharge

16. Anti-static Bags • Computer components are shipped in special plastic bags. • These bags protect the components inside from ESD • They should be saved and used to store the components that you work with • Storing components in these bags will reduce the risk of ESD damage to the component IT: Computer Maintenance - Safety & Electrostatic Discharge

17. Types Of Anti-static Bags Electrically conductive bags • Usually black or gray, coated with a metallic or carbon layer, or with a metallic weave • Metal helps conduct ESD across the surface of the bag to the ground very quickly • Carbon slows ESD transference, routing the charge to the ground • Bags can be used over long periods of time without losing effectiveness IT: Computer Maintenance - Safety & Electrostatic Discharge

18. Types of Anti-Static Bags (continued) Electrically Dissipative Bags • Usually pink, coated with a substance that slows the transference of ESD long enough for it to be conducted safely to the ground • Very little protection might actually be afforded to the components inside • Anti-static properties of the bag degrade over time IT: Computer Maintenance - Safety & Electrostatic Discharge

19. Summary • What Is Electrostatic Discharge (ESD)? • Why is ESD important? • ESD Damage • Preventing ESD Damage • ESD Workstation Components • ESD Wristband or Ankle Strap • ESD Floor or Table Mat • ESD Garments • ESD Gloves or Finger Covering • Increasing Humidity • Anti-static Bags IT: Computer Maintenance - Safety & Electrostatic Discharge