(800/900Mhz Transmitter Rf) - Motorola HT 1000 series Theory/Troubleshooting Manual

Replace
Ant Contact
BAD
Check
GOOD
Continuity at
Ant. Cont.
GOOD
Go to VCO
Chart #5B
YES
VDC
VDC
Base Q110
U105-7
NO NO
VDC
VDC
U101-2
U101-21
NO NO
Check
L105
MAEPF-23441-O
TROUBLESHOOTING FLOW CHART #1B

(800/900MHz Transmitter RF)

Check
YES
GOOD
Check
Continuity
S101
across
U104
BAD BAD
Replace S101 Replace U104
Replace U105
YES
RF
NO
Input Drive
U105-1
>1dB
YES
NO
VDC
U105-3, 4
YES
YES VDC YES
U101-7
NO
Check U102
D/A IC
YES
VDC
U102-11
NO
Check U102
D/A IC
No/Low Power
RF
YES TX
Input Drive
Current
U105-1
>500 mA
>1dBm
NO NO
Go to VCO
Chart #5B
VDC
at
Q108-2
YES
Check R101,
B+ VDC
U105-6
R103
NO
YES
VDC
VDC
U105-1
U105-2, 5
YES
OHM\
Q110
GOOD
Check U101
ALC IC
Check: U104,
CR101, R114,
C121, R110,
R111
DESCRIPTION
ILLUSTRATOR
SW
EDITOR
JWB
Go to DC Switch
Chart #3B
NO
Check E101,
E102, P404
NO
0.37 VDC
Check Q101
U101-12
& R129
YES
NO
NO
5 VDC VDC
U101-11 U101-13
YES
NO
VDC
Lock Det
See Chart #4
Cath.
NO
CR103
YES
VDC
Check D/A
U102-3
NO
YES
Chec R113
TECHNICAL PUB
DWG. NO.
JEDI
M
Troubleshooting Chart
DATE ENGINEER DATE PROGRAM D
C
Illustrator
3/12/93
DATE CHECKER DATE
CORRECTED
AS
3/31/93
MARKED
ISS.
LETTERING SIZE:
REQUIRES:
O
Check Continuity
Between U101-13
NO
& P404-1
Change ALC
U101
YES
35