Service manual

68P80401P01-O 7-1
CHAPTER 7
PREPARING FOR FIELD LEVEL TESTING
Field level testing requires external equipment and support. To conduct field level troubleshooting
and testing of an i870 unit, you must become familiar with the screen readouts of the recommended
test equipment.
Display screens provide information that is useful for troubleshooting purposes. Refer to Chapter 3
for information on the displays, errors, alert tones, and messages associated with this unit.
7.1 Preparing Equipment for Testing
To ensure accurate testing of the unit, it is important that the test equipment function properly.
7.1.1 Calibrating Equipment
Test equipment should be internally calibrated before being used for testing. Note that the internal
calibration does not substitute for a factory calibration. For more information, refer to R-2660
Digital Communications System Analyzer Operator’s Manual.
7.1.2 Checking the RF Cable
Check the cable connection and quality to ensure that the test results are true. Cable length is critical
to consistent Rx sensitivity and Tx power measurements. Use a high-quality, shielded, 50-ohm,
coaxial cable that is approximately 1.5 feet in length. Place the unit to be tested at least 6 inches
from the R-2660 Communications System Analyzer. The cable loss should be less than 2 dB.
7.1.3 Strong-Signal Environments
When using the R-2660 Communications System Analyzer to test a unit in a strong-signal
environment (–75 dBm or stronger), change the bandmap of the unit.
For Registration/Call testing: Power up the unit. Immediately after hearing the beep, press Start on
the R-2660. The unit will lock onto the first strong signal.
7.1.4 Protecting Static-Sensitive Devices
This unit contains static-sensitive devices that must be protected when opening the unit, or storing
and transporting any printed circuit board. Consider the following information to create a proper
ground:
• Ground the working surface of your service bench. If possible, use the Motorola Static
Protection Assembly (P/N 0180386A82) to ground your service bench. This assembly contains
a wrist strap, two ground cords, a table mat, and a floor mat.