Multitone RPR 583, Техническое руководство

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RPR 583
TM1212 Issue 1 Page 5 - 9
5.7 FAULT FINDING
5.7.1 General
Refer to the Fault Finding Guide (Figures 5.5 through 5.7) and the information given
in Tables 5.1 through 5.9 and Figures 5.8 through 5.11 to help resolve problems.
Alignment information is in paragraph 5.8. Programming information is given in
paragraph 5.9.
Faults can be caused by user negligence. Always check the unit for these faults:
a) Damage to the Case or LCD
b) Water damage
c) Corrosion damage or leaking battery
Any metal parts which are corroded must be removed. Clean the affected area of the
Board assembly with a non-corrosive contact cleaner. Dry the area with a low-
pressure flow of warm air (40
E
C through 50
E
C). Install new parts.
5.7.2 Fault Diagnosis
Put a known good battery in the unit and switch ON the unit. Refer to the Fault-
Finding Guide (Figures 5.5 through 5.7). If it is suspected that the Decoder Board
is faulty, proceed as follows:
a) Remove the Board Assembly from the case (see paragraphs 5.5.1 and 5.5.2).
b) Separate the Decoder Board from the Radio Board (see paragraph 5.5.3).
c) Disable the Battery Economy function by installing a 0 ohm resistor in the
position for R456 (side 2 of the radio board near IC401).
d) Use the 14-way lead (supplied with the P671B) to connect the two boards (refer
to Figure 5.4)
e) Put the boards on an anti-static mat and connect a 1.5 volt supply to the
Decoder Board. Switch ON the power supply.
f) Connect a ’10-times’ probe to the oscilloscope and measure the points given
in Table 5.4. Compare the waveforms on the oscilloscope with those shown in
Figure 5.9.
5.7.3 Power Supply Voltage Adjustment
There is no adjustment for the 1 volt, 1.5 volts or 3 volts power supplies.