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Measure the resistances of C530 - C535 (all six of class A, >200 kohms and in fig.
2.1)
Measure the resistances of C850 (>100 kohms, class A, fig. 2.1), C851 (>1 kohms,
class A, fig. 2.1), C833 (>1 kohms, class A, fig. 2.1) and C853 (>100 kohms, class
A, fig. 2.1).
Measure the voltages of VVCO and VRAD (~3.8V, fig. 2.2).
• If any of the voltages are incorrect, proceed to chapter 3 ("Doesn´t start"-fault).
Measure the DC voltage at pin 4 and 6 of N303 (fig. 2.1). The voltage at pin 4 (con-
trol voltage) should always vary between 0.8-2.8V (usually starts at 1.7V). The volt-
age at pin 6 (feed voltage) should also vary but usually starts at 3.3V.
• If the feed voltage is incorrect (usually missing), check the solderings at pins 8
and 102 of D600 (fig. 2.2). Also, check the solderings at D103 and 105 (fig. 2.2).
* If the solderings are correct, use the schematics.
• If the control voltage is incorrect (usually 0V or 3.6V), check the solderings at
pins 106-108 and 8 of D600.
* If they're correct, replace N301 (class B, fig. 2.1).
Check the solderings at Z250, Z500, Z201 (GSM900), Z202 (GSM1800, all in fig.
2.2) and Z205 (fig. 2.3).
If the fault remains, send the phone to the next level.
4/00021-2/FEA 209 544/3.D
SH888, S868, Standare Electrical Repair
Fig. 2.2
7
(66)
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