Motorola ASTRO XTSTM 4000 Detailed Service Manual page 69

Troubleshooting Charts: DC Supply Failure
DC Supply Failure–Page 2
1
Check voltage at pin
1,2,3,6,7 & 8 of Q1302
Voltage =
SWB+
7.5V +/-
20% ?
Yes
Check voltage at
R1320
Voltage =
SWB+?
Yes
Check voltage at
C1337
Voltage =
?
Yes
2
6871620L01-C
Check voltage at
No
R1311
(FET_ENX)
Check L1307,
No
L1308, R1320,
R1321, C1342 &
C1343
No
Replace Mainboard
No
Voltage =
GND?
Yes
No
Component
= OK?
5-7
Replace Mainboard
Replace Q1302
Replace problem
components
May 28, 2008