Motorola APX 5000 Service Manual page 122

5-16
5.4.2 DC Supply 3.6 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 U6504 and
verify enable input 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
Check No
Q6501
Replace
VOCON
board
Verify all other voltages are present
(i.e. 1.85, 1.4, etc) since if they are
Yes
absent, radio IC's maybe preventing
Yes Check L6502 No
for damage
values that are out of spec
Check if
No
U2204 is
damaged
V_SW_3.6 supply
Is radio
drawing > 100mA
from battery
or power
supply?
Yes
Are connectors
Yes
J4001 to P2001
shorted or
damaged?
No
Remove
VOCON
shield(s)
Verify SW_B+ is
present at C6565
Voltage
level
correct?
Yes
Voltage level correct
for V_SW_3.6
at C6561?
No
MAKO from turning on and
generating V_SW_3.6
No
Check for unstable output
voltage due to C6560,
C6561 or L6502 having
for U6504
No
Check if U6508
is loading down
V_SW_3.6
No
Check for
No
short to GND
at J1001-37
or J4001-41
Troubleshooting Charts: DC Supply Failure
Replace board
with damaged
connectors
Check Q6502 and No
Q6503 for damage
Check for
Yes short to GND
at J2001-41,
P2001-28
Refer to other
troubleshooting
charts for these
voltage supplies
excessive current for
GPS_BT_3.3v sources
Replace
Expansion
board excessive current for
GPS_BT_2.8v sources
Replace
VOCON
board
No
Check if
BlueTooth U2401
is drawing
excessive current
No
Check if
regulator U2402
is drawing
No
Check if
regulator U2405
is drawing