●
Intermittent
– Intermittent failures represent approximately 80 percent of ESD-related failures. The high rate of
intermittent failures means that most of the time when damage occurs, it is not immediately recognizable. The DIMM
receives a static shock, but the tracing is merely weakened and does not immediately produce outward symptoms related to
the damage. The weakened trace may take weeks or months to melt, and in the meantime may cause degradation of memory
integrity, intermittent memory errors, etc.
The more difficult type of damage to recognize and troubleshoot is the intermittent (also called latent or "walking wounded")
failure.
Perform the following steps to prevent ESD damage:
●
Use a wired ESD wrist strap that is properly grounded. The use of wireless anti-static straps is no longer allowed; they do not
provide adequate protection. Touching the chassis before handling parts does not ensure adequate ESD protection on parts
with increased sensitivity to ESD damage.
●
Handle all static-sensitive components in a static-safe area. If possible, use anti-static floor pads and workbench pads.
●
When unpacking a static-sensitive component from its shipping carton, do not remove the component from the anti-static
packing material until you are ready to install the component. Before unwrapping the anti-static packaging, ensure that you
discharge static electricity from your body.
●
Before transporting a static-sensitive component, place it in an anti-static container or packaging.
User warning guide
CAUTION:
All repairs must be done by a certified service technician. Opening the tablet violates ATEX/IECEx
certifications and warranties. You should only perform troubleshooting and simple repairs as authorized in
your product documentation, or as directed by online or telephone service and support team. Damage due to
servicing that is not authorized by Dell is not covered by your warranty. Read and follow the safety instructions
that came with the product.
WARNING:
The battery must only be charged outside of any potentially explosive environment with appropriate
Dell power adapters.
WARNING:
The I/O and battery bay covers must be closed with both screws tightened before the system is
exposed to a potentially explosive environment.
WARNING:
Do not remove the battery or access the I/O ports while the system is exposed to a potentially
explosive environment.
WARNING:
Do not connect external devices to any of the system ports while the system is exposed to a
potentially explosive environment.
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
Field service information
13
Summary of Contents for Latitude 7220EX
Page 20: ...20 Field service information ...
Page 22: ...22 Field service information ...
Page 31: ...Field service information 31 ...
Page 32: ...32 Field service information ...
Page 35: ...Field service information 35 ...
Page 36: ...36 Field service information ...
Page 52: ...52 Field service information ...
Page 54: ...54 Field service information ...
Page 59: ...Field service information 59 ...
Page 62: ...62 Field service information ...