Tait TM8100 mobiles Service Manual page 390

Task 30 —
Repair Circuitry
390 Transmitter Fault Finding (25W)
If the RF output power measured in
circuit between the common drain of the PAs and the test capacitor.
1. If not already done, remove the
2. Check for faulty, shorted or misplaced components in the circuit
between the test capacitor and the common drain of Q309 and Q310
(see Figure 12.6).
3. Repair any fault revealed by the above checks and go to
fault could be found, go to
4. Remove the test lead and test capacitor, resolder the coupling
capacitors C348, C349 and C350 in position (see
and go to Task
5. With the test lead still connected to the test set, enter the CCTM
command 326 5 to set the transmitter power level to the maximum.
Enter the CCTM command 101 x x 0, where x is the lowest
6.
frequency (in hertz) for maximum power, as given in
(A4 band), Table 12.9
Table 12.11 (D1 band) or
Enter the CCTM command 33 to place the radio in transmit mode.
7.
8. Measure the RF output power. This should exceed 35 W.
RF output power: more than 35W
Enter the CCTM command 32 to place the radio in receive mode.
9.
Enter the CCTM command 101 x x 0, where x is the highest
10.
frequency (in hertz) for maximum power, as given in
(A4 band), Table 12.9
Table 12.11 (D1 band) or
11. Repeat Steps Step 7
12. Remove the test lead and test capacitor, and resolder the coupling
capacitors C348, C349 and C350 in position (see
13. If the power in both the above cases is now correct, the fault has been
rectified; go to
failed; replace the board and go to
Task 29
PAF TOP
Step 4.
25.
(B1 band), Table 12.10
Table 12.12
(B1 band), Table 12.10
Table 12.12
to Step 9.
"Final Tasks" on page
"Final Tasks" on page
© Tait Electronics Limited November 2007
is low, there is a fault in the
can.
Step
Figure 12.16),
Table 12.8
(C0 band),
(H5, H6 bands).
Table 12.8
(C0 band),
(H5, H6 bands).
Figure 12.16).
163. If it is not, the repair
163.
TM8100/TM8200 Service Manual
5. If no