Motorola SSETM 5000 - Manual (Page 101)

Chapter 8 Troubleshooting
The purpose of this chapter is to aid in troubleshooting problems with the SSE 5000 radio. It is
intended to be detailed enough to localize the malfunctioning circuit and isolate the defective
component.
8.1 Voltage Measurement and Signal Tracing
It is always a good idea to check the battery voltage under load. This can be done by checking the
OPT_B+_VPP pin at the accessory connector (pin 8). The battery voltage should remain at or above
7.0 Vdc. If the battery voltage is less than 7.0 Vdc, then it should be recharged or replaced as
necessary prior to analyzing the radio.
In most instances, the problem circuit may be identified using a multimeter, an RF millivoltmeter,
oscilloscope (preferably with 100 MHz bandwidth or more), and a spectrum analyzer.
8.2 Standard Bias Table
Table 8-1 outlines some standard supply voltages and system clocks which should be present under
normal operation. These should be checked as a first step to any troubleshooting procedure.
When checking a transistor or module, either in or out of
circuit, do not use an ohmmeter having more than 1.5 Vdc
appearing across test leads or use an ohms scale of less than
x100.
Table 8-1. Standard Operating Bias
Signal Name Nominal Value Tolerance VOCON Board Source
13 MHz 13 MHz ±1000 ppm C303
FLIP_32K 32.768 kHz ±400 ppm R337
CKIH 16.8 MHz R615
16_8MHz 16.8 MHz C607
POR 3.0 Vdc ±5% R725
RESET_OUT 3.0 Vdc ±5% D401, pin 1
VSW1 3.85 Vdc ±5% Test point TP501
VSW2 1.85 Vdc ±5% Test point TP500
FILT_B+ 7.5 Vdc 6.0-9.0 Vdc C523
V2 3.0 Vdc ±5% R560
GCAP_B+ 7.5 Vdc 6.0-9.0 Vdc R581
UNSW_B+ 7.5 Vdc 6.0-9.0 Vdc B702
SW_B+ 7.5 Vdc 6.0-9.0 Vdc R587
VCC5 5.0 Vdc ±5% R503
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C a u t i o n