
August 16, 2007
6816985H01-B
6.3-18
UHF2 Troubleshooting Charts:
UHF Range 2 Frequency Generation Unit Troubleshooting Chart
6.3.19UHF Range 2 Frequency Generation Unit Troubleshooting Chart
FGU No LO/
TX Unlock
Is Vdc at VC_TP
0.4<Vdc<12?
Do a continuity
check and refer to
DC switch chart
Is Vdc at C269 high
at RX and low at TX
and C292 high at TX
and low at RX?
Take a
continuity
check of
traces to U201
Is Vdc=4.55V at pin
3 of Q271 during TX
and at Q251 during
RX?
Is Vdc=4.55V at pin
3 of Q272 during TX
and at Q252 during
RX?
For TX: Check D271-D274,
L271, L272, C271, C272, C273,
C274
For RX: Check D251-D254,
L252, L253, C251, C252, C253,
C256
Is there a voltage
reading at R205,
R204 and C210
directed to U201
Replace U202
Is Vdc at C218 3V
and C244 5V?
Is Vdc at Y200 pin 4
3V ?
Do a continuity
check and refer to
DC switch chart
Do you see 16.8MHz
at pin 3 of Y200 and
168_TP connection to
Xtal K9 pin of
U202 ?
Replace Y200
and/or C214
Do you see 16.8MHz
at C245?
Check U201
circuitry
Fix or replace
U201
Replace
U202
Do you see 11.5Vdc
at pin 2 of D202 ?
Is 3Vdc at pin 4 of
D201?
Check D201, D202,
C206, C207, C208 and
C209
Replace
U202
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
Yes
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: ......