Motorola APX 5000 Service Manual page 127

Troubleshooting Charts: DC Supply Failure
5.4.7 DC Supply 1.4 Volt Failure
Verify battery or
battery eliminator
contacts are
connecting to the
RF board's
spring contacts
Yes
Verify connectors
J1001 to P101 are
seated correctly
and not damaged
Yes
Remove RF board
and ohm across
P101
(pins 28 thru 36)
and B+
(battery contact)
at the RF board
and verify fuse
F200 is intact
(i.e. not blown)
No
Replace RF
board
Check V_1.55 to
verify enable input
at U6507 is present
No
MAKO
damaged
Replace
VOCON
board
No
Remove
VOCON
shield(s)
Verify
UNSW_B+ is
present at
Test Point:
F_UNSW_B+
No
No
Check
Q6501
Replace
VOCON
board
Verify all other voltages are present
(i.e. 3.6, 1.85, etc) sice if they are
Yes
absent, radio IC's maybe preventing
MAKO from turning on and
Check for
Yes
damage to
L6505
No
Check if OMAP U6302
No
is drawing excessive
curent from V_SW_1.4
thru E6502
V_SW_1.4 supply
Is radio
drawing > 100mA
from battery
or power
supply?
Yes
Are connectors
J4001 to P2001 Yes
shorted or
damaged?
No
Remove
VOCON
shield(s)
Verify SW_B+ is
Check Q6502 and
present at C6565 Q6503 for damage
Voltage
level
correct?
Yes
Voltage level correct
for V_SW_1.4
at C6586?
No
generating V_SW_1.4
No
Refer to other
troubleshooting
charts for these
voltage supplies
Replace board
with damaged
connectors
Replace
No
VOCON
board
5-21