TM8100 Mobile Radio Service Manual Diagnosis of Faults on Main Board 177
May 2004 © Tait Electronics Limited
Tas k 4 —
Check Digital Power-up
Signals
The radio may be configured for one or more of the power-up options
listed in Table 9.1. A particular option is implemented by inserting the
link mentioned in the table. The activation mechanism is the condition
that results in the digital power-up signal at pin 5 [at 6F6/6E6] of IC602
(see Figure 9.1) becoming active.
The functioning of the power-up options may be checked as described
in Steps 1 to 4 below; information on rectifying faults is also given. If
there is a fault with a particular power-up option for which the radio is
configured, carry out the procedure described in the relevant step.
1. For the 13V8-power-sense option the link LK1 [at 6C6/6E3]
should be inserted (see Figure 9.2). Check the power-up signal
while first disconnecting and then reconnecting the 13.8 V DC
supply at the power connector. The signal should go high when
the power is reconnected. If it does, return to Subsection 8.1. If
it does not, check for continuity and shorts to ground between the
link LK1 and the +13
V8 BATT input at the power connector PL100.
Repair any fault and return to Subsection 8.1.
2. For the auxiliary-power-sense option the link LK2 [at 6B6/6E2]
should be inserted (see Figure 9.2). Connect +3.3 V DC (more
than 2.6 V to be precise) from the power supply to the
AUX GPI3
line (pin 4 of the auxiliary connector SK101). Check that the
power-up signal is high. Remove the +3.3 V supply and ground
the
AUX GPI3 line (to be precise the voltage on the line should be
less than 0.6 V). If the signal is correct, return to Subsection 8.1.
If it is not, check for continuity and shorts to ground between
D601 [at 6C6/6E3] (see Figure 9.1) and pin 4 of the auxiliary
connector. Repair any fault and return to Subsection 8.1.
3. For the emergency option the link LK3 [at 6B5/6D2] should be
inserted (see Figure 9.2). Connect the
AUX GPI2 line (pin 5 of the
auxiliary connector SK101) to ground. Check that the power-up
signal is high. Remove the connection to ground. If the signal is
correct, return to Subsection 8.1. If it is not, check for continuity
and shorts to ground in the path from D601 [at 6C5/6D3] (see
Figure 9.1), via Q600 [at 6C5/6D2] (see Figure 9.2), to pin 5 of
the auxiliary connector. Repair any fault and return to
Subsection 8.1.
4. For the internal-options-power-sense option the link LK4 [at
6B4/6C2] should be inserted (see Figure 9.2). Connect +3.3 V
DC (more than 2.6 V to be precise) from the power supply to the
IOP GPIO7 line (pin 15 of the internal options connector SK102).
Check that the power-up signal is high. Remove the +3.3 V
supply and ground the
IOP GPIO7 line (to be precise the voltage on
the line should be less than 0.6 V). If the signal is correct, return
to Subsection 8.1. If it is not, check for continuity and shorts to
ground between D604 [at 6C4/6C3] (see Figure 9.1) and pin 15
of the internal options connector. Repair any fault and return to
Subsection 8.1.
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