Dc Supply Failure - Motorola APX 5000 Service Manual

Troubleshooting Charts: DC Supply Failure
5.4

DC Supply Failure

5.4.1 DC Supply 5 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
(pin 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 U6505 for
enable input and
voltage output lines
No
MAKO damaged
No
Measure if USB accessories
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. 1.85, 1.4, etc) since if they are
Yes
absent, radio IC's maybe preventing
MAKO from turning on and
No
Yes
Check L6504 Check Q6505 and
for damage Q6506 for damage
V_SW_5 supply
Is radio
drawing > 100mA
from battery
or power
supply?
Yes
Yes
are shorting VBUS line
No
Are connectors J4001
Yes
to P2001 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_5
at C6567?
No
generating V_SW_5
No
Refer to other
troubleshooting
charts for these
No
voltage supplies
Replace
VOCON
board
Remove accessory
or cable and replace
with good device
Replace board
with damaged
connectors
Replace
No
VOCON
board
Check for short
Yes No
to GND at
J2001-49 and
P2001-51
Check if
U2101
is drawing
excessive current for
audio controller
Replace
Expansion
board
5-15
No