Check Logic Signal; Check Lock Status; Receiver Fault Finding - Tait TM9100 Service Manual

If there is no fault with the power supplies, check the logic signal
Task 3 —

Check Logic Signal

that is input from the digital board.
1.
2.
3.
4.
5.
If the logic signal from the digital board is active, as required, check the lock
Task 4 —

Check Lock Status

status of the radio.
1.
2.
3.
4.
5.
232

Receiver Fault Finding

Check the logic signal
DIG RX EN
The signal is active high. The required status is active.
pin 8 of IC403: about 3.0V (active)
An alternative measurement point to the above is pin 24 of IC400
under the can (see
IF TOP
If is active, go to
DIG RX EN
Check the signal continuity from the digital board to the receiver.
Repair any fault and go to
be faulty, replace the main-board assembly and go to
page 147.
Recalibrate the receiver using the calibration application.
Confirm the removal of the fault and go to
page 147. If the repair failed, go to
Enter the CCTM command 72 to determine the lock status.
The status should be normal:
lock status: 111 (LO1, FCL, LO2 all in lock)
If the lock status is normal, go to
to "Frequency Synthesizer Fault Finding" on page
not in lock, go to "Power Supply for FCL" on page
is not in lock, go to Step
Check the components around IC403, Q402 and Q403
(see Figure 10.2). Repair any fault.
Recalibrate the receiver using the calibration application.
Confirm the removal of the fault, and go to
page 147. If the repair failed go to
at pin 8 of IC403 (see
Figure 10.1).
Task 4. If it is not, go to
Step 4. If the digital board itself appears to
"Final Tasks" on
Task 7.
Task 5. If the LO1 is not in lock, go
3.
"Final Tasks" on
Task 7.
© Tait Electronics Limited August 2005
DIG RX EN
Figure 10.2).
Step 3.
"Final Tasks" on
169. If the FCL is
215. If the LO2
TM9100 Service Manual