Tait TP9100 - Page 152

152 Power Supply Fault Finding TP9100 Service Manual
© Tait Electronics Limited May 2005
Reconnect the 7.5V external supply and turn the power/volume
control on. Measure the voltage across C631 (see Figure 8.2).
If it is correct, the fault is in the digital area. If not, the fault is on the
+3V3 rail excluding the digital area. If no fault can be found visually,
try to remove the ICs on the relevant rail. Locate and repair the fault.
9. Repair
LINK602 (see Figure 8.2), reconnect the external 7.5V power
supply and turn on the radio. If the radio powers up, go to “Final
Tasks” on page 134. If the radio fails to power up, the repair failed;
replace the main board and go to “Final Tasks” on page 134.
10. Disconnect the 7.5V external supply. Check for continuity and faults
around IC610, D601, L600, R626, R627, R628, and C630 (see
Figure 8.2), and repair any faults
11. Repair
LINK603, reconnect the external 7.5V power supply and turn
on the radio. If the radio powers up, go to “Final Tasks” on page 134.
If the radio fails to power up, the repair failed; replace the main board
and go to “Final Tasks” on page 134.
voltage across C631: 3.3V DC