Samsung SGH-S300 User manual

SGH-S300
SERVICE
Manual
GSM TELEPHO NE C O N TEN TS
1. Specification
2. Exploded View s and Parts List
3. Ele c tric a l P a rts List
4. B lock Diagram s
5. PC B Diagram s
6. Flow Chart of Troubleshooting and
CircuitDiagram s
GS M TELEPH O N E

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1. SGH-S300 Specification
1-1
GSM 900
Phase 1
EG SM 900
Phase 2
D C S1800
P hase 1 PC S1900
Freq. B and[M H z]
Uplink/Downlink
890~915
935~960
880~915
925~960
1710~1785
1805~1880
1850~1910
1930~1990
A R FC N range 1~124 0~124 &
975~1023 512~885 512~810
T x/R x spacing 45M H z 45M H z 95M H z 80M H z
M od. B it rate/
B it P e rio d
270.833kbps
3.692us
270.833kbps
3.692us
270.833kbps
3.692us
270.833kbps
3.692us
Tim e Slot
Period/Fram e Period
576.9us
4.615m s
576.9us
4.615m s
576.9us
4.615m s
576.9us
4.615m s
M odulation 0.3G M SK 0.3G M SK 0.3G M SK 0.3G M SK
MS Power 33dB m ~13dB m 33dB m ~5dB m 30dB m ~0dB m 30dB m ~0dB m
Pow er C lass 5pcl ~ 15pcl 5pcl ~ 19pcl 0pcl ~ 15pcl 0pcl ~ 15pcl
S e n sitiv ity -102dB m -102dB m -100dB m -100dB m
TD M A M ux 8 8 8 8
C ell R adius 35K m 35K m 2K m -
1. G S M G en eral S pecification

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1-2
SGH-S300 Specification
TXPower
control level GSM 900
533¡2dB m
631¡2dB m
729¡2dB m
827¡2dB m
925¡2dB m
10 23¡2dB m
11 21¡2dB m
12 19¡2dB m
13 17¡2dB m
14 15¡2dB m
15 13¡2dB m
16 11¡3dB m
17 9¡3dB m
18 7¡3dB m
19 5¡3dB m
TX Power
control level D C S1800
030¡3dB m
128¡3dB m
226¡3dB m
324¡3dB m
422¡3dB m
520¡3dB m
618¡3dB m
716¡3dB m
814¡3dB m
912¡4dB m
10 10¡4dB m
11 8¡4dB m
12 6¡4dB m
13 4¡4dB m
14 2¡5dB m
15 0¡5dB m
TX Power
con trol level PC S1900
030¡3dB m
128¡3dB m
226¡3dB m
324¡3dB m
422¡3dB m
520¡3dB m
618¡3dB m
716¡3dB m
814¡3dB m
912¡4dB m
10 10¡4dB m
11 8¡4dB m
12 6¡4dB m
13 4¡4dB m
14 2¡5dB m
15 0¡5dB m
2. G S M T X p ow er class

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6. SGH-S300 Flow Chart of Troubleshooting and CircuitDiagram s
6-1
1
.Baseband
1. P ow er O N
Check the current
consum tion m ore than
100m A
Check the
Vbat(battery+O)
Voltag e m o r e th an
3.3V
Dow nloader again
NO
Charge the Battery
NO
Check U 100 and C113
NO
YES
YES
YES
YES
'
Pow er O n' does not
work
C heck the pin
15 of U 100 ismore
than 2.8V
U100 pin 46,39
=2.8V
U 100 pin13
=1.8V
Check the clock signal
at
pin4 of U 801
Freq=13M H z ?
Vrms¡˘¡300m V ?
Vpp is around
900m V pp
Check the clock generation circuit
(re lated to O SC 801 and U 801)
NO
'
Pow er O n' does not
work
YES
END
YES
Check U 114 and C116
NO
Check U 112
NO

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6-2
SGH-S300 Flow Chart of Troubleshooting and CircuitDiagram s
2.Initial
3. Sim Part
Che ck the sign al a t the
pin28ofU100is
"H igh" w hen the phone
isbooton
Check the pin 22 of
U 100 is"High"
C heck U 100
NO
Check the U 700
NO
Check th e s o ld e re d s ta tu s o f
O SC801, R803, U 100
NO
YES
YES
YES
I
n itial F ailure
C heck the pin4 of
OSC801 isaround2.8V
C h ec k a nd re so lder LC D connector C N 200
ifthere is s olde r b ridh e be tw e en the p ins
EN D
YES
Check the SIM
co nn ec tor's (CN100)
connector's to S IM card
C he ck the circ uit relate d to
U 100
NO
r
esolder or change C N 100
NO
Che ck the related circuitof
C N 100
NO
YES
YES
YES
Phone can't a cce ss S IM ca rd
C he ck the circ uit a ro un d U 60 1 o utp ut
and voltag e sup ply c ircu itry
EN D
YES
Check the pin 1 of CN 100.
Voltage=3V?
C he ck the circu it aro un d C N 1 0 0 inp ut
circ u itry
C he ck the related circuitof
U 601 and U 100
NO

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SGH-S300 Flow Chart of Troubleshooting and CircuitDiagram s
6- 3
4. C harging Part
Check U 100
NO
Check the U 700
NO
Check the Q 101
NO
YES
YES
YES
Abn orm al c ha rg ing part
EN D
YES
Check the pin 17,18 of
CN302 VEXT is > 4V?
C heck the pin 2 of U 103
is"LOW"?
C heck the pin 3 of Q 101
is"LOW"?
C heck the pin 5 of U 102
is"3.2~ 4.2"?
Check if ICHRG is1V
(du ring ch arging ) an d
arou nd 1 80 m V (full
ch arging )
YES
Check the U 102
NO
Resolder or change R 111
NO

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6-4
SGH-S300 Flow Chart of Troubleshooting and CircuitDiagram s
5.M icrophone Part
6. Speaker P art
Check the reference
voltage on m ic path
C418 =2.5V
R e ass em blag e m icrophone
NO
r
esolder or change
C400,R 428,R 409,R 405,R 406)
NO
Check U 700
NO
YES
YES
Microphone does not w ork
EN D
YES
Che ck the asse m bled
sta tu s o f m icrop ho n e.
Ismicrophone ok?
R e solde r and ch e ck th e bo ard
to board connector
NO
Check U 601
NO
Cha ng e or re so lder
U 700, R201, R202
NO
YES
YES
YES
Speaker does not w ork
EN D
C heck the connection
statu s sp k to C N 20 0
Check the PIN 1 of
U402='High' ?
Check U700,R201,R202
Is s pe ak er o k?
YES
Change Speaker
NO

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SGH-S300 Flow Chart of Troubleshooting and CircuitDiagram s
6- 5
7.Back Light
END
Select backlight "O N " m ode
NO
Check the U 601
NO
YES
YES
YES
Back light does not w ork
YES
Back lig h t "O N " m o d e in
the m eue?
Check the PIN 3 of
200-1 = 2.8V ?
C heck the connection
fro m C N 2 0 2 to L C D
Module
YES
Rep lace FPCB CONNECTOR
NO
Cha ng e L C D M o du le
NO
Ch eck th e so ld ere d sta tus of EL pad
LCD backlight on?

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6-6
SGH-S300 Flow Chart of Troubleshooting and CircuitDiagram s
8.Alert T on e
Check th e co nn ec tion
from C N 200-1 to LC D
Module
C he ck the circ uit relate d to
U 400,U 401
NO
Change Speaker
NO
Cha ng e L C D M o du le
NO
YES
YES
Abn orm al A lert tone
END
YES
Check the P IN 17, 18 of
CN200-1
Is th ere alert w ave?
A lert isok?
A lert ton e O n by p ush ing the key
*# 02 8 9#

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SGH-S300 Flow Chart of Troubleshooting and CircuitDiagram s
6- 7
2
.RF
1. G S M R eceiver
CONTINUOS RX ON
RF IN PU T : 62CH
Cell pow er : -50dB m
NORM AL CONDITION
ca tch the channel?
F1002 CHECK
pin13 ¡ˆ -65dB m ?
F1002 CHECK
pin1,2 ¡ˆ-65dB m ?
U901 CHECK
pin21,22 ¡ˆ-65dB m ?
CHECK
C1012,L 1015,C 1002 contact?
NO
CN1001
re s o lder or change
NO
F1002
res olde r o r cha ng e
NO
C1007,L 1001,C 1011
re s o lder or change
NO
YES
YES
YES
U901
pin 1 2,13 ¡ ˆ
20dBm ?
U 902 CH EC K
pin5,25,28 : 3V ?
U 902 CH EC K
pin7:13MHz?
OSC801 CHECK
pin3:13MHz?
V p-p : 950m V ?
OSC801 CHECK
pin4:clean
3V ?
U901 CHECK
pin14,23,26,32 :
3V ?
U 901 Pin3,4
V p-p:240m V ? U900 CHECK
pin 6 ,20 : 2.8V ?
U 901 Pin1,2
V p-p:250m V ?
U 900
Pin 2 ,3 ,4 ,5
V p-p:100m V ?
U100,PIN 39,C116
ch ec k o r res olde r
U902
change or resolde r
C808, R805
re solde r
OSC801
ch an ge
U100,PIN 46,C114
res olde r o r cha ng e
U900
res olde r o r cha ng e
L1006,C 1015,C 1019
re s o lder or change
NONO
NO
NO NO
NO
NO
NO
NO
NO
YES
YES YES
YES YES YES
YES
YES
YES
YES
YES