Tait TP9100 Service Manual page 172

Task 9 —
If the supply for the charge pump and the reference frequency are correct,
Line
DIG SYN EN
check the
1.
2.
3.
4.
5.
6.
7.
8.
172 Frequency Synthesizer Fault Finding
line input.
DIG SYN EN
Check the line at pin 10 of IC503 (see
DIG SYN EN
Enter the CCTM command 334 0 to switch off the synthesizer, and
measure the voltage at pin 10.
pin 10 of IC503: 0V DC (after entry of CCTM 334 0)
Enter the command 334 1 to switch on the synthesizer, and measure
the voltage again.
pin 10 of IC503: 2.5 ± 0.3V DC (after entry of CCTM 334 1)
If the voltages measured in
Task 10. If they are not, go to
Remove can.
DIG BOT
Enter the CCTM command 334 0 to switch off the synthesizer, and
measure the voltage on both sides of R716 (see
R716: 0V DC (after entry of CCTM 334 0)
Enter the CCTM command 334 1 to switch on the synthesizer, and
measure the voltage on both sides of R716 (see
R716: 3.3 ± 0.3V DC (after entry of CCTM 334 1)
If the voltages measured in
check whether the IO port (D2) of IC701 is faulty or shorted by
solder. If the voltages are correct, go to
If there is a fault, repair the circuit, confirm the removal of the fault,
and go to "Final Tasks" on page
could be found, replace the main board, and go to
page 134.
Figure
Step 1 and Step 2 are correct, go to
Step 4.
Figure
Figure
Step 5 and Step 6 are still not correct,
Step 8.
134. If the repair failed or no fault
"Final Tasks" on
TP9100 Service Manual
© Tait Electronics Limited May 2005
9.2).
9.6).
9.6).