TM9100 Service Manual Transmitter Fault Finding (50W/40W Radios) 255
© Tait Electronics Limited August 2005
Task 3 —
9V Power Supply
If the supply from the power connector is correct, check the 9V DC supply.
1. Enter the CCTM command 326 1 to set the transmitter power level
very low.
2. Enter the CCTM command 33 to place the radio in transmit mode.
3. Measure the supply voltage between the 9
V0 TX test point and the
GND test point (see Figure 11.6).
4. Enter the CCTM command 32 to place the radio in receive mode.
5. If the supply measured in Step 3 is correct, go to Task 4
in
“Transmitter RF Power” on page 259. If it is not, the 9V regulator
IC601 and the associated switching circuitry Q603 are suspect; go to
Task 3
of “Power Supply Fault Finding” on page 158.
supply 9V0 TX: 9.0 ± 0.5V DC