Motorola GP344 Detailed Service Manual page 22

2-4
To replace a component on a flexible circuit:
1. grasp the edge of the flexible circuit with seizers (hemostats) near the part to be
removed
2. pull gently
3. apply the tip of the soldering iron to the component connections while pulling with the
seizers.
NOTE Do not attempt to puddle out components. Prolonged application of heat may damage
the flexible circuit.
Chip Components
Use either the RLN4062 Hot-Air Repair Station or the Motorola 0180381B45 Repair Station for
chip component replacement. When using the 0180381B45 Repair Station, select the TJ-65 mini-
thermojet hand piece. On either unit, adjust the temperature control to 370 °C (700 °F), and
adjust the airflow to a minimum setting. Airflow can vary due to component density.
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To remove a chip component:
1. Use a hot-air hand piece and position the nozzle of the hand piece approximately 0.3 cm
(1/8") above the component to be removed.
2. Begin applying the hot air. Once the solder reflows, remove the component using a pair
of tweezers.
3. Using a solder wick and a soldering iron or a power desoldering station, remove the
excess solder from the pads.
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To replace a chip component using a soldering iron:
1. Select the appropriate micro-tipped soldering iron and apply fresh solder to one of the
solder pads.
2. Using a pair of tweezers, position the new chip component in place while heating the
fresh solder.
3. Once solder wicks onto the new component, remove the heat from the solder.
4. Heat the remaining pad with the soldering iron and apply solder until it wicks to the
component. If necessary, touch up the first side. All solder joints should be smooth and
shiny.
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To replace a chip component using hot air:
1. Use the hot-air hand piece and reflow the solder on the solder pads to smooth it.
2. Apply a drop of solder paste flux to each pad.
3. Using a pair of tweezers, position the new component in place.
4. Position the hot-air hand piece approximately 0.3 cm (1/8" ) above the component and
begin applying heat.
5. Once the solder wicks to the component, remove the heat and inspect the repair. All
joints should be smooth and shiny.
MAINTENANCE