Ares Communications Technology . , INC
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2051P Service manual 1~3 V3.0- .doc
DB-2051P Service Manual
2004/12/17 Page 45 of 90
Confidential Document
SYMPTOM 13
Calls cannot be made (dial malfunction).
After
switch on
Check:
1.
whether IC9_13~IC9_16 have a signal,
I/Q signal shown in figures 9 and 10, and
2.
whether IC9_1, IC9_2, IC9_3, and IC9_5
have a control signal.
Re-solder or
replace IC7.
Power supply: check whether the DC
voltage of IC9_48, IC9_40, IC9_29,
IC9_20, IC9_6, and IC9_7 is 2.8V.
Check whether the output
voltage of IC6_31 and
IC6_37 is 2.85V, and check
C60, C57 and so on;
re-solder or replace the
part(s) in worst case.
Check by a spectrum analyzer:
For GSM: whether IC9_18 and
IC9_19 have a signal as shown in
figures 11 and 12,
or
For DCS: whether IC9_23 and
IC9_24 have a signal as shown in
figures 13 and 14.
Check:
GSM: IC9, C22, C18, and
C155,
or
DCS C13, R8, C12, C11, R7,
R30, and C26; re-solder or
replace the part(s) in worst
case.
Check by a spectrum analyzer:
For GSM: whether IC5_4 and
IC5_5 have a signal as shown in
figures 15 and 16,
or
For DCS: whether IC5_2 and
IC5_3 have a signal as shown in
figures 17 and 18.
Check:
GSM: R25, L1, L3, C14, L18,
L8, C8, and C30, or
DCS C45, L2, L19, L12, R53,
C43, C76, and C35; re-solder
or replace the part(s) in worst
case.
A
Y
Y
Y
Y
Y
N
N
N
N
