Testing and Alignment Procedure
CHATNOW
75028XXXX series
1. Recommended Test Equipment
1.1 HP8920A Communication Test Set
1.2 Fluke 50S Digital Thermometer
1.3 Fluke 77 Digital Voltmeter
1.4 Power Supply
1.5 Thermometer with digital display
2. Test Preparation
2.1 Connect a 6.0Vdc power source to the positive terminal input point and the
negative battery input point (GND) for negative terminal.
2.2 Connect a communication test set to the antenna test point.
2.3 Connect a 1 watt 16ohm resistor from sSP to -SP.
2.4 Test point +SP should be connected to Audio In HI of the HP8920A.
2.5 Test point -SP should be connected to Audio In LO of the HP8920A.
3. Voltage Regulator Test
3.1 Connect a voltmeter to output of regulator TP11 (VCC) and measure the
voltage. The DC value must be between 3.45 to 3.58Vdc.
4. Low_Battery Detect Alignment
4.0 Connect a voltmeter to TP10(LOW_BATT).
4.1 Adjust power supply to 4.80Vdc +/- 10mV.
4.2 Select one resistor from R112 to R114 until the voltmeter reading is close to
2.25Vdc +/- 40mV. Unit will beep
5. Battery ICON Level Test
5.1 Adjust power supply to 5.4Vdc +/- 50mV.
5.2 Cycle power by turning the unit Off then On.
5.3 Check 2 segmentsof the battery level icons are solid.
5.4 Adjust power supply to 5.0Vdc +/- 50mV.
5.5 Cycle power by turning the unit Off then On.
5.6 Check 1 segment of the battery level icons are solid.
5.7 Adjust power supply to 4.3Vdc +/- 50mV.
5.8 Cycle power by tuning the unit Off then On.
5.9 Check segments of the battery level icons are shell.
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