(800/900Mhz Frequency Generation Unit - Fgu) - Motorola Handie-Talkie MTX Series Theory/Troubleshooting Manual

FGU No Lo Injection/TX
Check Continuity
Between
U204-2 & J704-6
NO
U204-3 & J704-15
U204-4 & J704-17
If no Fault Found
Replace U204
No 2.1MHz
Go to VCO
YES
TX/RX Unlock
Routine
Chart #5B
Check
YES
C256, C257,
C258 & CR204
TROUBLESHOOTING FLOW CHART #4B

(800/900MHz Frequency Generation Unit - FGU)

Unlock
A
VDC at
YES
V Con Pin 1
U205
<0.7V
?
NO
5V at
NO
U204 Pin 11, U202 Pin 1,
20, 23, 2 & 8 OK
25, 42?
NO
VDC at
U204 Pin 21,
Refer to
28, 38
Chart #3B
OK
?
YES
13V
16.8MHz
NO
at U204
Pin 36?
YES
2.1MHz
NO
at U204
Pin 10?
YES YES
VDC at
CR204
Pin 6
OK?
NO
2.5V
Replace
at U204
U204
Pin 8 & 9
NO
?
ILLUSTRATOR
SW
EDITOR
JWB
Replace
U204
YES
VDC at
?
NO
NO
at U204
Pin 14?
YES
2.5V
at U204
Pin 14?
DATE ENGINEER DATE PROGRAM DISK
C68
Illustrator
3/12/93
DATE CHECKER DATE
CORRECTED
AS
3/22/93
MARKED
ISS. REVISION
LETTERING SIZE:
REQUIRES:
O
Check Continuity
YES Between
Replace
U203-24 & J704-5
U203
U203-22 & J704-15
U203-24 & J704-8
VDC at
16.8MHz
NO
U203-9,
at U203
13, 14, 23
Pin 10?
YES
Check
R222/C284
CHECK
ONE
( )
O.K. AS IS
( )
O.K. AS MARKED
RLSE. RLSE.
JWB SW
3/31/93 3/31/93
YES
NO
41