TM8100/TM8200 Service Manual
Fault Finding of Control Head with Graphical Display
409
© Tait Electronics Limited
June 2006
If the signal is not correct, check the 13.8V supply voltage from the
radio body. Return to
3.
Check the inhibit signal at pin 3 of U1.
If the signal is above 2.2V, visually inspect the components D1, R16,
R17, R208, and Q201 for open or shorted contacts. Replace if nec-
essary. Return to
If the signal is low, replace U1. Return to
.
4.
Check the 1.5V supply voltage at pin 4 of U203.
If the signal is correct, continue with
If the signal is not correct, continue with
.
5.
Check E203 for continuity.
If E203 is correct, continue with
If E203 is faulty, replace E203 and return to
6.
U202 detects a possible power failure and generates an output signal
on pin 7. Check whether this signal is low.
If pin 4 measures 3.3V and pin 7 is low, replace U202.
If pin 4 measures 3.3V and pin 7 is high, replace U203.
U1 pin 3: high: >2.2V, low: < 0.7V
D1: V
s
– 5.1V
U203 pin 4: 1.5V
E203: 1.5V
U202 pin 4: 3.3V
U202 pin 7: 3.3V
Figure 14.2
PCB layout of the power supply circuitry
top side
Junction of C210 and E202
Summary of Contents for TM8235
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 04 Issue 4 June 2006...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 62: ...62 Description TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 148: ...148 Disassembly and Reassembly TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 162: ...162 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 178: ...178 Interface Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 258: ...258 Receiver Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 446: ...446 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...