Motorola APX 3000

Troubleshooting Charts: DC Supply Failure 5-21
5.4.7 DC Supply 1.4 Volt Failure
Yes
Verify Q6501
Voltage
= 1.5V?
Yes
Voltage
1.8V?
Refer troubleshooting
guide 5.4.5
No
Verify UNSW_B+
at test point:
F_UNSW_B+
Yes
Voltage
2.775V?
No
Check if U6302
draining high
current thru E6502
V_SW_1.4
Voltage
1.8V?
Yes
No
No
Verify L200, C202
and C203 is good.
No
Replace fuse
Check external
circuitry for U6507.
If good, change
U6507.
Yes