No Output Power At Tx Mode (136-174 Mhz); Figure 5-13. No Output Power At Tx Mode (136-174 Mhz) - Motorola ASTRO XTL 1500 Detailed Service Manual

5-22
5.6.11 No Output Power at TX Mode (136–174 MHz)
Replace U0951
9.3V_Tx_regulator
Reset the radio
and than press
PTT button
Replace U0958
Go to PA
troubleshooting
June 15, 2005
Start
Press PTT button
Measure the
volt age
at TP0951
s
No
9.1V < V < 9.6V
?
s
No
V < 2.6V
?
s
Yes
V = 0V
?
s
No
P < +0dBm
?
Figure 5-13. No Output Power at TX Mode (136–174 MHz)
Troubleshooting Charts: Flowcharts
Measure the
Yes
volt age
at TP0961
Measure the
Yes
volt age
at TP0942
s
No
V > 4.5V
?
Yes
Using a high
impedance prob,
measure RF level
at U3550 pin 16
Go to TX injection
Yes
troubleshooting
No
Replace U3550
Perform Power
tune
6815854H01-A