Motorola HT Series Detailed Service Manual page 93

Maintenance: General Repair Procedures and Techniques
To remove a chip component:
1. Use a hot-air hand piece and position the nozzle of the hand piece approximately 1/8" (0.3
cm) 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
component. 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 1/8" (0.3 cm) 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.
• Shields
Removing and replacing shields are recommended to be done with the Air Blower, BOSCH GHG
603 or equivalent.
To remove the shield:
1. Place the circuit board in the circuit board holder.
2. Add solder paste flux around the base of the shield.
3. Position the heat-focus head onto the shield.
4. Turn on the heater and wait until the shield lifts off the circuit board.
5. Once the shield is off, turn off the heat, and grab the part with a pair of tweezers.
6. Remove the circuit board from the circuit board holder.
To replace the shield:
1. Add solder to the shield if necessary, using a micro-tipped soldering iron.
2. Next, rub the soldering iron tip along the edge of the shield to smooth out any excess solder.
Use solder wick and a soldering iron to remove excess solder from the solder pads on the
circuit board.
3. Place the circuit board back in the circuit board holder.
4. Place the shield on the circuit board using a pair of tweezers.
5. Position the heat-focus head over the shield .
6. Turn on the heater and wait for the solder to reflow.
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