Motorola APX 3000 Basic Service Manual page 111

Disassembly/Reassembly Procedures: Ensuring Radio Submergibility
8.7.7 Immersibility Test
Immersibility testing the radio is necessary only if the radio has failed the vacuum test. Do not
perform the test until the vacuum test has been completed. Immersibility test involves creating
sealed condition inside the radio, submerging the radio in water, and observing the radio for a stream
of bubbles (leak). Since all areas of the radio are being checked, observe the entire unit carefully for
the possibility of multiple leaks before completing this test.
NOTE: When Radio is placed under the water there will be some air trapped which will be released.
This is not a failure.
Refer to the exploded view diagrams and parts lists found in Exploded Views and Parts Lists.
To conduct the immersibility test:
1. Observe if there is any torn on the main o-ring and battery contact seal.
2. Ensure that the front kit and back kits are assembled properly.
3. Cover the ventilation hole with a brand new Seal, Vacuum Port and label gore port.
4. Attach a long string to the radio and submerge the radio into a water-filled container with the
depth of 1m.
5. Watch for any continuous series of bubbles. A steady stream of bubbles indicates a sign of
leakage.
6. Note all of the seal areas that show signs of leakage. Rotate the radio to view all sides to
pinpoint the problem(s) to one (or more) of the following areas:
• Seal Interfaces
• Battery Contact Seal
• Front Housing, including the Top Bezel
• Chassis
7. Remove the radio from the water container and dry the radio thoroughly. Be especially careful
to dry the area around the vacuum Port and the battery contact seal area.
8. See Troubleshooting Leak Areas.
Some accumulation of air may be entrapped in the main
housing which may cause a false diagnosis of a leak. Ensure
there is a steady stream of bubbles before concluding there is
a leak.
To avoid equipment damage, keep the area inside the Battery
contact pocket is dry before assembling battery.
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