
August 16, 2007
6816985H01-B
6.5-22
900 MHz Troubleshooting Charts:
900MHz Transmitter RF Troubleshooting Chart
6.5.23900MHz Transmitter RF Troubleshooting Chart
MAEPF-27349-O
No/Low TX Power
Is B+ at
U101 pins 6,7,
and 14?
Is Vdc
at TP101
>2V?
Is Vdc
at U101 pin 1
>2V?
Is Vdc
at C142
>1V?
Is
RF at U101
pin 16 >2
dBm?
No
No
Yes
Yes
Yes
Yes
Is
RF at U101
pin 6 >20
dBm?
Yes
Yes
Yes
Yes
No
Is
TX current
>300mA?
Is RF
input drive at
U101 pin 16
>2dBm?
Is there
continuity across
U106?
Go to Frequency
Generation Unit
Chart
No
Check L107
and L108
No
Check E101,
E102 and L103
No
Check ALC IC
No
Check R114,
R115, and R119
No
Replace Q101
No
Go to Frequency
Generation Unit
Chart
No
Check L110,
C101, C114,
C116, C161,
C162 and C164
Replace U101
Is B+
at C128?
Change U106
No
Yes
Yes
No
Is
voltage drop
across CR101
>0.5V?
Is
there RF
at connector
J101?
Check U102
and the ALC IC
Check L114, L115,
C127, C129, C131,
C132 and C133
Remove SH102
Check CR102,
and R103
Yes
Check C128,
C127, C219,
and C142
*
*
*
*
*
*
*
*
*
For Analysis, shields SH103 and SH104 need to be removed.
= Transmitter enable Low.
Summary of Contents for ASTRO MT 1500
Page 4: ...iv Table of Contents August 16 2007 6816985H01 B Notes ...
Page 164: ...August 16 2007 6816985H01 B 5 6 Troubleshooting Procedures Operational Error Codes Notes ...
Page 188: ...August 16 2007 6816985H01 B 6 1 24 VHF Troubleshooting Charts Secure Hardware Failure Notes ...
Page 212: ...August 16 2007 6816985H01 B 6 2 24 UHF1 Troubleshooting Charts Secure Hardware Failure Notes ...
Page 236: ...August 16 2007 6816985H01 B 6 3 24 UHF2 Troubleshooting Charts Secure Hardware Failure Notes ...
Page 710: ...9 2 40 UHF1 Schematics Board Overlays and Parts Lists August 16 2007 6816985H01 B Notes ...
Page 806: ...9 5 32 900MHz Schematics Board Overlays and Parts Lists August 16 2007 6816985H01 B Notes ...
Page 816: ...Index 4 August 16 2007 6816985H01 B Notes ...
Page 817: ......