Motorola XTS 2500 Service Manual page 212

6.2-22
6.2.23UHF Range 1 Transmitter RF Troubleshooting Chart
No/Low TX Power
Is
Yes
TX current
>300mA?
No
No
Is B+
at L119?
Yes
Is B+ at
No
U101 pins 6,7,
and 14?
Yes
*
Is Vdc
No
at TP_146
>2V?
Yes
*
Is Vdc
No
at U101 pin 1
>2V?
Yes
*
Is Vdc
No
at R103
>1V?
Yes
*
Is
No
RF at U101
pin 16 >2
dBm?
Yes
*
Is
No
RF at U101
pin 6 >20
dBm?
Yes
Check C156, C159,
C160, L161, C157,
C158 and L139
February 14, 2012
UHF1 Troubleshooting Charts: UHF Range 1 Transmitter RF Troubleshooting Chart
*
Is RF
input drive at
U101 pin 16
>2dBm?
No
Go to Frequency
Generation Unit
Chart
Check E140
Check E102
and L130
For Analysis, shields SH103 and SH104 need to be removed.
Check U102 IC
Check R108
Replace Q200
Go to Frequency
Generation Unit
Chart
Check C150,
Replace U101
C169, C100
and L130
*
Is
voltage drop
across D170
>0.5V?
No
Check U102
and the ALC IC
= Transmitter enable Low.
*
MAEPF-27349-O
*
Is
Yes
there RF
at connector
J101?
No
Check C177, C174,
L172, C175, C172,
L171, C173, C170
and C171
Remove SH103
and Check
D171
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