Motorola APX 7500 - Page 124

September 9, 2011 68009482001
7-8 Troubleshooting Charts and Error Codes Troubleshooting Charts
Figure 7-6. Controller Board DC Voltages - B
No Yes
No
Yes
No
A+ present at U1300-2
VCC_5V
Yes
VCC_5V present at U1300-1
No Yes
No
Yes
No
SWB+
Yes
SWB+ present at Q1306-2
Yes
Yes
9.6V_WL
4.8V_WL
2.2V_WL
No
No
No
Yes
UNSW_3.3V
Yes
No
Yes
Yes
Yes
No
J6_IGNITION
CH_IGNITION
No
1
2
No
No
1
No
Yes
Yes
2
1
Is 5V present
at U1300-1?
Is 3V present
at U1300-7?
Is 3.3V
present at
Q1308-2?
Replace 5V
Regulator U1300.
Replace transistor
package Q1308.
Reprogram/
Replace
AVR U1311
Is 13.2V
present at
Q1306-2?
Does Q1306-1
measure 0V?
Is 3.3V
present at
Q1305-5?
Replace MOSFET
Q1306.
Replace transistor
package Q1305.
Reprogram/
Replace
AVR U1311
Is 9.6V
present at
R2315?
Is 4.8V present at
test point 4.8V_WL?
Is 2.2V
present at
R2321?
Is 3.3V
present at
R1346?
STOP
Verify 0 Ohm jumper R2315 is placed properly.
Verify R1320 is placed & measures 33.2K.
Verify R2317 is placed & measures 4.75K.
Check/Replace Voltage Regulator U1319.
Verify R2316 is placed & measures 33K.
Verify R1354 is placed & measures 18K.
Verify R1355 is placed & measures 15K.
Verify 0 Ohm jumper R2321 is
placed properly on the board.
STOP
Verify 0 Ohm jumper 1346 is
placed properly on the board.
Check/Replace Voltage
Regulator U1305.
Is 13.2V
present at
Q1311-2?
Does Q1311-1
measure 0V?
Replace MOSFET
Q1311.
Replace transistor
package Q1302.
STOP
Is 3.3V
present at
Q1302-1?
Is R1307 placed &
measure 4.7K?
Correctly place the
4.7K resistor
R1307.
Is R1315 placed &
measure 10K?
Correctly place the
10K resistor
R1315.