GH688,GA628, Standard Electrical Repairs
4/00021-2/FEA 209 544/1.G 46 (112)
Fig. 7.6
* If VDIG is too low, measure the resistance to ground.
* If it’s more than 500 ohms, replace N702 (class A).
* If it’s less than 500 ohms, send to next level.
* If VDIG is correct, measure the resistance of R716 (class A, ~4.7 ohms, fig.
7.5).
* If the resistance is correct, check the resistance from R716 to N702 pin 5
(~0 ohms) and from R716 (opposite side) to N705 pin 2 (~0 ohms).
* If any of the resistances are too high there is a foil damage and the
phone should be discarded.
* If the input voltage at N705 pin 2 is correct, measure the output voltage
VSIMPAD (~5V) at N705 pin 3 (class A, fig. 7.4).
* If the voltage is incorrect, replace N705.
* If there is correct voltage, it could be foil damage between N705 pin 3
and R724 or between N705 pin 3 and V700 pin 1/V705 pin 1 (fig. 7.5,
7.4). If there is a foil damage the phone should be discarded.
7.4 There is voltage at VSIMPAD.
Check the SIM-card holder and make sure that the SIM-card contacts aren’t dirty,
bent or broken.
Open the phone and check for liquid damage, especially below the SIM-card holder
(J603, fig. 7.4).
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