194 Diagnosis of Faults on Main Board TM8100 Mobile Radio Service Manual
May 2004 © Tait Electronics Limited
Task 3 —
CCTM Checks
If the signals at the TP501 and TP502 test points are correct, or any related
faults were rectified, perform the following CCTM checks:
1. Enter the CCTM command 393 1 1900. Note the voltage level;
this should be about 1.3 V DC. Then enter the CCTM command
72 and note the lock status.
2. Enter the CCTM command 393 1 –1900. Note the voltage level;
this should be about 2.1 V DC. Then enter the CCTM command
72 and note the lock status.
3. If the above voltage levels are not correct or if the FCL is out of
lock in either or both of the above cases, go to Step 4. If the
voltage level remains fixed at about 1.5 V DC, go to Step 5. If the
voltage levels are all correct (following earlier repairs), the fault has
been removed; return to Subsection 8.1.
Figure 9.12 FCL circuitry under the VCXO BOT can
SYN BOT CAN
CDC BOT CAN
CAN FOR
DIGITAL
BOARD
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