Motorola APX 7000 Detailed Service Manual page 113

Troubleshooting Charts: Power-Up Failure
Power-Up Failure – Low VBUS2 Voltage
Low VBUS2 Voltage
Measure
VCC_SW_5 at
R6544
5.1 < V < 5.6?
Yes
Measure VBUS1
Supply Volatge at
R6529
5.1 < V < 5.6?
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
Inspect Q6505 and
No
Supporting
Circuitry
Yes
Check Placement
of Q6503
Are Parts Solder
No
Connections and
Placement Correct
Yes
Replace VOCON
Board
No
Is Part Placed
Correctly
Yes
Replace VOCON
5-9
Repair Incorrect
Part/s
Replace Part