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2 No serv or can´t place call.
2.1
Connect the phone (with signaling program) to a GSM test instrument and try to get
serv at -68.5 dBm on the input signal. If the phone gets serv proceed to section 2.2.
If the phone doesn´t get serv, there is probably a fault in the LO part or too big
losses in the signal path. Open the phone and check for liquid damages. Make sure
the antenna connection X101 (class A) isn´t mecanically damaged, unsoldered or
dirty (varnish, glue, oxide...) (Fig 2.1).
Look for soldering faults on C318 (class A), N302 and N303 (all three Fig 2.1).
Measure the resistance of C530, C531, C532, C533, C534 and C535 (>200 kOhm,
all are class A, Fig 2.1).
Measure the resistance of C850 (>100 kOhm, class A, Fig 2.1), C851 (>1 kOhm,
class A, Fig 2.1), C833 (>1 kOhm, class A, Fig 2.1) and C853 (>100 kOhm, class
A, Fig 2.1).
Measue VVCO and VRAD (3.8V, Fig 2.2). If any of the voltages are incorrect, pro-
ceed to chapter 3 ("Doesn´t start"-fault).
Find out if the fault is related to
Rx(reciever) or Tx(transmitter).
C531
C530
C851
C833
4-00021-2/FEA 209 544/5.C
I888, Standard Electrical Repairs
C850
C853
9
8
20
1
N301
C318
Fig 2.1
C532
C535
C534
C533
X101
3
1
N303
6
4
N302
6
(42)
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