Vacuum Test; Pressure Test - Motorola EX500 Basic Service Manual

Ensuring Radio Immersibility
4. Remove the Battery Contact Seal from the Battery Contact on Main Board.
5. Inspect the Battery Contact on Main Board and surrounding areas for foreign material that
might prevent the Battery Contact Seal from sealing properly.
6. Install a new Battery Contact Seal; discard the old Seal.
7. Reassemble the housing.
CAUTION: The main seal O-ring should not be visible when looking at the back side of the radio. If the
seal is visible, it is improperly installed.
Continue reassembling the radio according to Section 3.14 "EX560•XLS Radio Reassembly —
Detailed" on page 3-24. Tighten all hardware that was loosened or removed.

3.15.9 Vacuum Test

The vacuum test uses a vacuum pump and gauge. The pump creates a vacuum condition inside the
radio, and the gauge monitors the radio for a stable vacuum reading; that is, checking for a properly
sealed, watertight unit. Before starting the vacuum test:
Remove the battery
•
Remove the universal connector dustcover to expose the universal connector.
•
Remove the breathing vent label and breathing vent membrane.
•
To conduct the vacuum test:
1. Attach the vacuum hose to the vacuum pump. Check the pump and hose for leaks by
blocking off the open end of the hose and operating the pump a few times. The actual reading
of the gauge at this point is not important; it is important that the gauge pointer remained
steady, indicating no vacuum leaks in the pump.
2. Ensure that the fitting seal is attached to the hose-to-chassis pump connector. Screw the
pump connector into the tapped hole in the chassis.
3. Attach the open end of the hose to the pointed end of the pump connector.
4. Place the radio on a flat surface with the chassis facing upward.
5. Operate the pump until the gauge indicates 6 in. Hg of vacuum on the radio. Observe the
gauge for approximately 1 minute.
If the needle falls 1 in. Hg or less (for example, from 6 in. Hg to 5 in. Hg), then the radio
•
has passed the vacuum test and is approved for immersibility. No additional testing will
be required.
If the needle falls more than 1 in. Hg (for example, from 6 in. Hg to less than 5 in. Hg),
•
then the radio has failed the vacuum test and the radio might leak if immersed.
Additional troubleshooting of the radio will be required; complete this procedure, then go
to Section 3.15.10 "Pressure Test".
6. Remove the vacuum hose and pump connector from the radio.

3.15.10Pressure Test

Pressure testing the radio is necessary only if the radio has failed the vacuum test. Do not perform
the pressure test until the vacuum test has been completed. Pressure testing involves creating a
positive pressure condition inside the radio, immersing 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.
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