Motorola Astro Digital Mobile Radio Xtl5000 Detailled 6881096c74 B Manual

6881096C74-BMay 25, 2005
Troubleshooting Charts: Troubleshooting Tables 5-11
Table 5-4.  XTL 5000 Receiver Troubleshooting Table (VHF Band)
SymptomCheck SectionTroubleshooting ProcedureComponent
Poor Sensitivity Front-end • Check 2.85 V on pin 4 and 0 V 
on pin 5 of U3250• U3250.
• Check transistors Q3250, 
Q3252 VCE levels. Levels 
should be
~ 5 V• Q3250, Q3252 (only Q3252 in 
STD mode).
• Using a RF probe, check for 20 
dBm on TP6771• FGU section.
• Verify that all Front-end 
components are well...

May 25, 20056881096C74-B
5-12Troubleshooting Charts: Troubleshooting Test Points
5.4 Troubleshooting Test Points
The following figures show the location of the main board test points for measuring voltages and 
viewing waveforms.
Figure 5-1.  Main Board Test Points—Top Side (for Mid Power)
Figure 5-2.  Main Board Test Points—Bottom Side (for Mid Power)
MAEPF-27802-O
ID7
ID6 ID5 ID3ID4
ID2ID1 ID0
MAEPF-27801-O 

6881096C74-BMay 25, 2005
Troubleshooting Charts: Board ID Jumper Configuration 5-13
Figure 5-3.  Main Board Test Points—Top Side (for High Power)
Figure 5-4.  Main Board Test Points—Bottom Side (for High Power)
5.5 Board ID Jumper Configuration
The following jumper table (Table 5-5 on page 5-14) is provided for troubleshooting and determining 
what board revision you have. This can be helpful in the event a jumper was placed incorrectly or 
was removed during a repair and the radio is not functioning...

May 25, 20056881096C74-B
5-14Troubleshooting Charts: Flowcharts
The table indicates what the logic levels are, as well as how they correlate to the placement or 
removal of a jumper to accomplish the logic level. This is because some of the board ID resistors are 
on Pull-Up I/O pins and some are on Pull-Down I/O pins. Therefore, the placement or removal of a 
resistor for a Pull-Up I/O is the opposite of what must be done for the placement or removal of a 
resistor for a Pull-Down I/O.
Refer to the...

6881096C74-BMay 25, 2005
Troubleshooting Charts: Flowcharts5-15
5.6.1 Poor RX Sensitivity or No RX Audio (136–174 MHz)—Part 1 of 2
Figure 5-5.  Poor RX Sensitivity or No RX Audio (136–174 MHz)—Part 1 of 2

	




 
  
  
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May 25, 20056881096C74-B
5-16Troubleshooting Charts: Flowcharts
5.6.2 Poor RX Sensitivity or No RX Audio (136–174 MHz)—Part 2 of 2
Figure 5-6.  Poor RX Sensitivity or No RX Audio (136–174 MHz)—Part 2 of 2

	



 


 





 
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6881096C74-BMay 25, 2005
Troubleshooting Charts: Flowcharts5-17
5.6.3 RX IF—Poor SINAD or No Audio (136–174 MHz)
Figure 5-7.  RX IF—Poor SINAD or No Audio (136–174 MHz)

	


 	
 

  	
 
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May 25, 20056881096C74-B
5-18Troubleshooting Charts: Flowcharts
5.6.4 RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 1 of 3
Figure 5-8.  RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 1 of 3

	


 
  


  
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6881096C74-BMay 25, 2005
Troubleshooting Charts: Flowcharts5-19
5.6.5 RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 2 of 3
Figure 5-9.  RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 2 of 3
 


  
	
 


		
 
 
 
	
 
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May 25, 20056881096C74-B
5-20Troubleshooting Charts: Flowcharts
5.6.6 RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 3 of 3
Figure 5-10.  RX Back-End—Poor SINAD or No Audio (136–174 MHz)—Part 3 of 3







	
 	

 

  

   


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