Motorola ASTRO Digital Saber Service Manual page 102

FGU No Lo Injection/TX
Unlock
A
VDC at
YES Replace
V Con Pin 1
U302
U307
<0.7V
?
NO
5V at
VDC at
U302 Pin 11, NO
U305 Pin 1,
20, 23,
2 & 8 OK
25, 42?
NO
Check Continuity
Between
VDC at
U302-2 & J401-9
NO
Refer to DC
U302 Pin 21,
U302-3 & J401-10
Switch
U302-4 & J401-14
28, 38
Chart C.35
If no fault found,
OK
replace U302.
?
YES
13V
16.8MHz
NO
at U302
at U302
Pin 36?
Pin 14?
YES
No 2.1MHz
2.1MHz
2.5V
NO
at U302
at U302
Pin 10?
Pin 14?
YES YES
Go to VCO
YES VDC at
TX/RX Unlock
CR301
Routine
Pin 6
Chart C.34
OK?
NO
YES
Check 2.5V
Replace
at U302
C301, C302,
U302
Pin 8 & 9
C350 & CR301
?
NO
Chart 32 . 800MHz Frequency Generation Unit (FGU)
10-20
YES
?
NO
Check Continuity
YES Between
Replace
U304-24 & J401-5
U304
U304-22 & J401-15
U304-24 & J401-8
YES
VDC at
16.8MHz
NO NO
U308-9,
at U304
13, 14, 23
Pin 10?
YES
YES
Check
NO
R306/C309
MAEPF-24390-A
NO