Tait TM8100 mobiles Service Manual page 427

Figure 14.2 PCB layout of the power supply circuitry
TM8100/TM8200 Service Manual
© Tait Electronics Limited November 2007
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.
U1 pin 3: high: >2.2V, low: < 0.7V
D1: V – 5.1V
s
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.
U203 pin 4: 1.5V
If the signal is correct, continue with
If the signal is not correct, continue with
5. Check E203 for continuity.
E203: 1.5V
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.
U202 pin 4: 3.3V
U202 pin 7: 3.3V
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.
Fault Finding of Control Head with Graphical Display
Step 1.
Step 1.
Step
Step 6
Junction of C210 and E202
top side
Step 1.
6.
Step 5.
Step 4.
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