Motorola SSETM 5000 Troubleshooting, Voltage Measurement and Signal Tracing, Standard Bias Table

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.

8.1Voltage 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

7.0Vdc. 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.

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

C a u t i o n x100.

8.2Standard Bias Table

Table 8-1outlines 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.

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