400
Fault Finding of Control Head
TM9100 Service Manual
© Tait Electronics Limited
August 2005
14.2
Power Supply Faulty
A 3.3 V regulator (U1) converts the switched 13.8V supply from the radio
body to 3.3 V. A 1.5 V regulator (U203) converts the 3.3 V to 1.5V.
A power-sense module (U202) verifies the outputs of the voltage regulators
and—in the case of a fault—creates a power reset signal which is processed
by the FPGA. If the start-up of the control head fails, the radio body reduces
the switched 13.8V supply shortly after power is supplied.
For all faults, check that the supply voltages are correct:
1.
Check the 3.3V supply voltage between E202 and C210.
If the signal is correct, continue with step
4
.
If the signal is not correct, visually inspect the components E202,
D201, L201, R205, and R206 for open or shorted contacts.
Replace if necessary. Continue with step
2
.
2.
Check the 13.8V supply voltage (9.7V to 17.2V) between pin 2 of
the control-head connector J103 and pin 8 of U1.
If the signal is correct, continue with step
3
.
Note
A fault in the control head can cause the radio body to reduce the
switched 13.8 V supply shortly after power is supplied. In this case,
the control head must be supplied directly through pin 2 of con-
nector J103.
Figure 14.1
Circuit diagram of the power supply circuitry
J103
6
2
13V8
L1
C205
C207
C11
D1
R16
R17
R208
Q201
C206
C12
C13
R18
INH
COMP
SYNC
VCC
GND
U1
VREF
FB
OUT
2
4
3
8
1
6
5
7
GND
L201
D201
R205
R206
C14
+
E202
C210
3V3
IN
OUT
U203
EN
RST
GND
3 6
1
2
4
5
3V3
PFI
U202
PFO
MR
RST
WDI
WDI
GND
5
3
1
6
7
8
2
4
E203
1V5
C204
R201
S201
D203
D203
K1
K2
AA
AA
3V3
FPGA
R210
C201
C202
R202
R204
DNI
PWR WDT
MR
PWR RESET
1V5
3V3
1
2
R203
Control-
Head
Connector
E202/C210: 3.3V
J103 pin 2: 13.8V (V
s
=9.7V…17.2V)
U1 pin 8:
13.8V (V
s
=9.7V…17.2V)
Summary of Contents for TM9100
Page 1: ...TM9100 mobiles Service Manual MMA 00017 01 Issue 1 August 2005 ...
Page 4: ...4 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 10: ...10 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 22: ...22 Introduction TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 62: ...62 Description TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 96: ...96 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 138: ...138 Disassembly and Reassembly TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 152: ...152 Servicing Procedures TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 168: ...168 Interface Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 244: ...244 Receiver Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 396: ...396 CODEC and Audio Fault Finding TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 420: ...420 Fault Finding of Control Head TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 426: ...426 Spare Parts TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 430: ...430 TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 444: ...444 TMAA04 05 Ignition Sense Kit TM9100 Service Manual Tait Electronics Limited August 2005 ...
Page 448: ...448 TMAA10 01 Desktop Microphone TM9100 Service Manual Tait Electronics Limited August 2005 ...