Replacing Smt Components; Handling Smd Resistors And Capacitors; Static Precautions; Soldering/Desoldering Smd Components - Cyrus 6 Service Manual

CYRUS 6 & 8 – Replacing SMT Components
Handling
SMD resistors and capacitors are widely used in the Cyrus range of products. When handling
SMD components, certain precautions should be observed-

Handling SMD resistors and capacitors

Always store SMD components in their original packaging or in a cool dry environment.
Always handle SMD resistors and capacitors with tweezers or a vacuum pencil.
Never handle SMD resistors and capacitors with fingers.
Hold the SMD component by the body, not by the ends.
Do not use SMD resistors or capacitors if the ends are dirty or discoloured.
Do not use SMD resistors or capacitors if they have been dropped on the floor- they may
be internally damaged.
Always use replacement components of the correct size and shape. SMD components are
available in many different packages. Where possible, order original parts from Cyrus.
Handling SMD ICs
Always store these components in their original packaging or in a cool dry environment.
Always handle SMD transistors and ICs with tweezers or a vacuum pencil.
Never handle SMD transistors and ICs with fingers.
Ensure that the connection pins of larger multi-pin ICs are not deformed or damaged
before fitting.
Measuring circuits with SMD capacitors and resistors
Avoid using sharp, pointed probes directly on the component end caps.
Measure voltages from the PCB pad next to the component.

Static precautions

SMD components, particularly ICs, may be damaged by the static levels present in the workshop.
Damage caused by static may not immediately cause component failure but could cause partial
damage and a possible failure in the future. Observing these simple SMD precautions will avoid
product failures related to static damage-
Always wear a grounded wristband when replacing any electronic components.
Always store components in their original packaging or conductive plastic bags.
Never store components in plastic trays or bags without protection.

Soldering/desoldering SMD components

Never re-use old SMD components after de-soldering!
Always apply solder heat directly to the contact area. Avoid over-heating adjacent
components.
Always repair SMD PCBs with the correct tools. SMD components can only be replaced
with a hot air pencil or soldering iron designed for SMD components, preferably with
temperature control.
8 Jan 2006