Motorola APX 5000 Service Manual page 115

Troubleshooting Charts: Power-Up Failure
Power-Up Failure – Low VBUS2 Voltage
Low VBUS2 Voltage
Measure
V_SW_5 at
C6567
5.1 < V < 5.6?
Yes
Measure VBUS1
Supply Volatge at
R6529
Yes
Inspect U6503 and
Supporting Ciruitry
Are Parts Solder
Connections and
Placement Correct
No
Repair Incorrect
Part/s
Proceed to Low
No
SW5 Volatge Flow
Chart
Yes
Check Placement
of Q6503
No
Is Part Placed
Correctly
Yes
Replace VOCON
5-9
Replace Part