Mag One BPR 40 Service Manual - page 24
2-4
Repair Procedures and Techniques – General
Flexible Circuits
The flexible circuits are made from a different material than the rigid boards, and require different
soldering techniques. Excessive prolonged heat on a flexible circuit can damage the material.
Therefore, avoid excessive heat and excessive bending.
For parts replacement, use the ST-1087 Temperature-Controlled Solder Station with a 600-700
degree F tip, and use small diameter solder such as ST-633. The smaller size solder will melt faster
and require less heat to be applied to the circuit.
To replace a component on a flexible circuit:
1.
Grasp with seizers (hemostats) the edge of the flexible circuit 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.
Chip Components
Use the RLN4062 Hot-Air Repair Station for chip component replacement. Adjust the temperature
control to 370°C (700°F), and adjust the airflow to a minimum setting. Airflow can vary due to
component density.
•
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.
•
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 compo-
nent. If necessary, touch up the first side. All solder joints should be smooth and shiny.
•
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.
NOTE
Do not attempt to puddle-out components. Prolonged application of heat may damage the
flexible circuit.