Motorola APX 3000

5-14 Troubleshooting Charts: Power-Up Failure
Power-Up Failure – Low V_EXT_1.85 Voltage
Low V_ENT_1.85 Voltage
Measure Radio
Current
Is standy
current > 15mA
above avg?
Board has a short,
replace board
Measure
V_SW_3.6
Voltage at R6510
No
Yes
Voltage =
V_SW_3.6
Proceed to
Incorrect
V_SW_3.6
Voltage
Measure Voltage
R6431 on V_5.0A
Side
No
Yes
4.8 < V < 5.2
Measure Voltage
at R6431 on
BGAP_COMP
side
Yes
Proceed to Low
LD08 V_5.0A
Voltage Flow
Chart
No
2.2 < V < 2.7?
Measure Voltage
at R6420
Inspect U6508 and
All Supporting
Circuitry
Yes
Yes
No
Inspect and repair
U6409 and
Replace Main
Board
No
Are Parts Solder
Connections &
Placement Correct
Replace or repair
Parts
Replace Main Board
No
2.2 < V < 2.7?
Supporting
Circuitry