Ericsson T18s Trouble-Shooting Instruction page 43

* If the signal (SIMRST) is missing, do the same test, but at D600 pin 73.
* If SIMRST is missing here too, replace D600 (class B).
* If SIMRST exists (at D600 pin 73), then there is a foil damage, and the
board has to be discarded.
* If SIMRST exists at D901 pin 7, measure SIMCONRST at D901 pin 8.
* If SIMCONRST is missing (at D901 pin 8), replace D901.
* If SIMCONRST exists at D901 pin 8, replace R600 (33 ohm) and meas-
ure again at J603 pad 2.
* If the signal is still missing, there is a foil damage between D901 pin
8 and J603 pad 2.
SIMCONCLK
Measure at the SIMCONCLK- pad (see Fig. 7.1) while starting the phone. The
phone sends 5 pulses with the amplitude 5 V at start up, these pulses are modulated
with a clock signal (see Fig. 7.2).
• If SIMCONCLK is missing, do the same test as above, but at D901 pin 6 (see
Fig. 7.1). The signal (SIMCLK) should look the same, but with the amplitude
3.2 V.
* If the signal (SIMCLK) is missing, do the same test, but at D600 pin 75.
* If SIMCLK is missing here too, replace D600 (class B).
* If SIMCLK exists (at D600 pin 75), replace R998 (class A) and measure
again at D901.
* If SIMCLK is still missing, then there is a foil damage, and the board
has to be discarded.
* If SIMCLK exists at D901 pin 6, measure SIMCONCLK at D901 pin 9.
* If SIMCONCLK is missing (at D901 pin 9), replace D901 (class A).
* If SIMCONCLK exists at D901 pin 9, replace R627 (0 ohm, class A)
and measure again at J603 pad 3.
* If the signal is still missing, there is a foil damage between D901 pin
9 and J603 pad 3.
4/00021-2/FEA 209 544/12.B
T18s, T18sc Standard Electrical Repairs
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