Ericsson I 888 Trouble-Shooting Instruction page 7

32
1
33
D105
128
D600
64
97
65
96
Measure the voltage on pin 4 and 6 on N303 (Fig 2.1). The voltage on pin 4 (the
control voltage) should always vary between 0.8-2.8 V (usually it starts at 1.7 V).
The voltage on pin (the feed voltage) is also variable, but usually it starts at 3.3 V. If
the feed voltage is incorrect (often is it missing completly), check the solderings on
D600:8, D600:102 and also on D105 and D103 (all at Fig 2.2). If the control voltage
is incorrect (mainly 0 or 3.6 V), check the solderings on D600:8 and D600:106-108.
If those are fine, replace N301 (class B, Fig 2.1).
Check the solderings on Z250, Z500, Z201 (GSM 900) and Z202 (GSM1900) (all at
Fig 2.2) plus Z205 (Fig 2.3).
If the fault still remains, send the phone to the next repair level.
4-00021-2/FEA 209 544/5.C
L560
1
B510
VRAD
VVCO
Z500
D103
Fig 2.2
P401
Fig 2.3
I888, Standard Electrical Repairs
1 28
N570
N560
14
15
Z250
Z202
Z205
Z204
L223
Z203
L403
N401
Z201
7
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