Motorola APX 3000 Detailed Service Manual page 99

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?
No
Measure VBUS2
Supply Voltage
at R6536
Yes
Inspect U6503 and
Supporting Circuitry
Are Parts Solder
Connections and
Placement Correct
No
Repair Incorrect Parts
Proceed to Low
Yes
SW5 Voltage Flow
Chart
Yes
Check Placement
of Q6508
No
Is Part Placed
Correctly
Replace Part
Yes
Replace Board
5-9