Motorola iDEN i930 Field Service Manual page 111

MECHANICAL PARTS REWORK AND REPAIR: Mechanical Parts Rework Procedure
1. Set proper temperatures.
2. With bottom heater ON, place the assembly on top of it to start pre-heating the PCB.
3. Place adequate Nozzle in the hand-piece of the Hot Air Machine.
4. Set desired air pressure.
5. Get the new component ready by fluxing it as per specifications.
6. Protect any heat-sensitive component by placing appropriate Heat Shield over (If necessary)
7. Lower the nozzle and evenly apply heat until reflow of all solder joints is observed.
8. Immediately remove component before solder joints re-solidifies.
9. Release faulty component onto a heat resistant surface.
10. Check for component disturbance before proceed and fix it if necessary.
9.9.2 Land Preparation Procedure
1. Swing out the top heater and maintain the board over the bottom heater.
2. Pre-fill and re-level the lands by fluxing the targeted area, re-flowing wire solder with a
soldering iron over each land uniformly. The quantity of solder applied is critical to achieving
acceptable joints.
3. Clean lands of flux residue.
9.9.3 Installation Procedure
1. Pick the new part and place it over the lands as per overlay or Pedro.
2. Swing in microscope to aid on component alignment.
3. Align part (Tack if necessary) and swing microscope out.
4. Carefully cover component with appropriate Heat Shield to protect it from degradation.
5. Lower nozzle over the component/Heat Shield and start the heating cycle.
6. Observe until re-flow is completed.
7. Rise nozzle and stop heat cycle.
8. Allow solder to re-solidify.
9. Cool off the PC board using bench fan.
10. Inspect solder joints and adjacent components under Microscope.
NOTE: Indium Indalloy NC771 flux pen (Motorola P/N 1185768C01) must be used for rework of
Bottom Connector and RF Connector. NO FINAL FLUX CLEAN UP IS ALLOWED to avoid flux
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