Motorola APX 7500 Detailed Service Manual page 134

7-18 Troubleshooting Charts and Error Codes Troubleshooting Charts
~300mVrms tone present
Verify R2830, R2831, C1871,
Is there a 1kHz,
No
C1872, U1802, C1851 & R2832
~300mVrms tone at
are placed properly & the
R2832?
resistor values are correct.
Is ~1.35Vdc
There may be an issue with the
No
present at U1802-10 &
internal board routing of
~3.3Vdc present at
VCC_1.35V and/or VCC_3.3V.
U1802-4?
Yes
Yes
Replace U1802.
Is there continuity Verify RX_AUDIO is being routed
No
between R2832 on the properly from R2832 through the
Mainboard & J24-1 on the flex cable & high speed board to
high speed board? J24-1.
Yes
STOP
Figure 7-16. Crosspatch RX Audio - B
September 9, 2011 68009482001