Motorola APX 5000 Service Manual page 124

5-18
5.4.4 DC Supply 1.85 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 for
short to GND
No
at J1001-6,
J2101-29,
J2304-12,
J4001-28
Check U6508 and
Yes
verify enable input
at R6543 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. 3.6, 1.4, etc) since if they are
Yes
absent, radio IC's maybe preventing
MAKO from turning on and
generating V_EXT_1.85
Check for
Check for damage to
No
damage to MUXES
Q6507 U6601, U6103,
U6104, U6105
Check if OMAP
U6302
No is drawing
excessive curent
from V_EXT_1.85
thru E6501
Troubleshooting Charts: DC Supply Failure
V_SW_1.85 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 Check Q6502 and
present at C6565 Q6503 for damage
Voltage
level
correct?
Yes
Voltage level correct
for V_EXT_1.85
at C6568?
No
No
Check for
damage to
No
voltage
translators
U2202, etc
No
Check if
CPLD U6101,
Audio codec U6605,
No
DDR U6301, or
FLASH U6302
are drawing excessive
current from V_EXT_1.85
Replace board
with damaged
connectors
No
Check for
Yes No
short to GND
at J2001-10, U2406, U2407,
P2001-28 U2408, U2409,
U2410, U2478,
U2414, U2473
Refer to other MACE U2501,
troubleshooting eMMC U2301,
charts for these BlueTooth U2401
voltage supplies are drawing excessive
current from V_EXT_1.85
Replace
VOCON
board
Check for
damage to
voltage
translators
No
Check if
No
Replace
Expansion
board