Chart 35. 800 Mhz Transmitter Rf - Motorola ASTRO XTS 3000 Service Manual

Replace
Ant Switch
BAD
Check
Check
GOOD GOOD
Check RF @
Continuity at Continuity
RF Connector
across
Ant. Switch
J2
U501
GOOD BAD
Check L102,
Replace U501
L105, C114,
C101, C108
Replace U502
YES
RF
NO
Go to VCO Input Drive
Chart #5B U502-1
>1dB
YES
YES VDC NO VDC
VDC
Base Q501 U502-2
U502-5
NO
NO
VDC VDC
YES
VDC
U504-E3 U504-C1
U504-E4
NO
NO NO
Check U503
D/A IC
Check
L101
VDC
U503-B5
NO
Check U503
D/A IC
No/Low Power
RF
TX
YES YES
Input Drive
Current
U502-1
>500 mA
>1dBm
BAD NO
NO
Go to VCO
Chart C.34
VDC
NO
Go to DC Switch
at
Chart C.35
Q503
YES
NO
Check E1, E2,
Check R507, B+ VDC
U502-4 E3, E4, J3
R508
YES
NO
VDC YES NO
VDC 0.37 VDC
U502-1
U502-3 U504-A3
YES
OHM\ 5 VDC
YES
Q501 U504-B2
GOOD
Check U504
VDC
ALC IC
Lock Det
Cath.
CR502
Check: U504,
CR501, R505,
YES
C503, R503,
R506
VDC
U503-E2

Chart 35. 800 MHz Transmitter RF

10-34
YES
Check Q502
& R509
Check Continuity
NO
Between U504-B3
NO
& J1-20
YES VDC YES
Change ALC
U504-B3
U504
NO
NO See Chart C.32
FGU Unlock
YES
NO
Check U503
D/A IC
YES
Check R501
MAEPF-26045-O