Dell Latitude 7220, Service Manual

Page: 8 / 84

ESD field service kit
The unmonitored Field Service kit is the most commonly used service kit. Each Field Service kit includes three main components: anti-
static mat, wrist strap, and bonding wire.
Components of an ESD field service kit
The components of an ESD field service kit are:
• Anti-Static Mat – The anti-static mat is dissipative and parts can be placed on it during service procedures. When using an anti-
static mat, your wrist strap should be snug and the bonding wire should be connected to the mat and to any bare metal on the system
being worked on. Once deployed properly, service parts can be removed from the ESD bag and placed directly on the mat. ESD-
sensitive items are safe in your hand, on the ESD mat, in the system, or inside a bag.
• Wrist Strap and Bonding Wire – The wrist strap and bonding wire can be either directly connected between your wrist and bare
metal on the hardware if the ESD mat is not required, or connected to the anti-static mat to protect hardware that is temporarily
placed on the mat. The physical connection of the wrist strap and bonding wire between your skin, the ESD mat, and the hardware is
known as bonding. Use only Field Service kits with a wrist strap, mat, and bonding wire. Never use wireless wrist straps. Always be
aware that the internal wires of a wrist strap are prone to damage from normal wear and tear, and must be checked regularly with a
wrist strap tester in order to avoid accidental ESD hardware damage. It is recommended to test the wrist strap and bonding wire at
least once per week.
• ESD Wrist Strap Tester – The wires inside of an ESD strap are prone to damage over time. When using an unmonitored kit, it is a
best practice to regularly test the strap prior to each service call, and at a minimum, test once per week. A wrist strap tester is the
best method for doing this test. If you do not have your own wrist strap tester, check with your regional office to find out if they have
one. To perform the test, plug the wrist-strap's bonding-wire into the tester while it is strapped to your wrist and push the button to
test. A green LED is lit if the test is successful; a red LED is lit and an alarm sounds if the test fails.
• Insulator Elements – It is critical to keep ESD sensitive devices, such as plastic heat sink casings, away from internal parts that are
insulators and often highly charged.
• Working Environment – Before deploying the ESD Field Service kit, assess the situation at the customer location. For example,
deploying the kit for a server environment is different than for a desktop or portable environment. Servers are typically installed in a
rack within a data center; desktops or portables are typically placed on office desks or cubicles. Always look for a large open flat work
area that is free of clutter and large enough to deploy the ESD kit with additional space to accommodate the type of system that is
being repaired. The workspace should also be free of insulators that can cause an ESD event. On the work area, insulators such as
Styrofoam and other plastics should always be moved at least 12 inches or 30 centimeters away from sensitive parts before physically
handling any hardware components
• ESD Packaging – All ESD-sensitive devices must be shipped and received in static-safe packaging. Metal, static-shielded bags are
preferred. However, you should always return the damaged part using the same ESD bag and packaging that the new part arrived in.
The ESD bag should be folded over and taped shut and all the same foam packing material should be used in the original box that the
new part arrived in. ESD-sensitive devices should be removed from packaging only at an ESD-protected work surface, and parts
should never be placed on top of the ESD bag because only the inside of the bag is shielded. Always place parts in your hand, on the
ESD mat, in the system, or inside an anti-static bag.
• Transporting Sensitive Components – When transporting ESD sensitive components such as replacement parts or parts to be
returned to Dell, it is critical to place these parts in anti-static bags for safe transport.
ESD protection summary
It is recommended that all field service technicians use the traditional wired ESD grounding wrist strap and protective anti-static mat at all
times when servicing Dell products. In addition, it is critical that technicians keep sensitive parts separate from all insulator parts while
performing service and that they use anti-static bags for transporting sensitive components.
Transporting sensitive components
When transporting ESD sensitive components such as replacement parts or parts to be returned to Dell, it is critical to place these parts in
anti-static bags for safe transport.
Lifting equipment
Adhere to the following guidelines when lifting heavy weight equipment:
CAUTION: Do not lift greater than 50 pounds. Always obtain additional resources or use a mechanical lifting device.
1. Get a firm balanced footing. Keep your feet apart for a stable base, and point your toes out.
2. Tighten stomach muscles. Abdominal muscles support your spine when you lift, offsetting the force of the load.
3. Lift with your legs, not your back.
8 Working on your tablet