ERICSSON EH238 ServTeleph
SERVICE: Telephone
Ericsson Handheld Telephone 1341-B
SERVICE: Telephone
2
Contents
SERVICE: Telephone
Connectors and Signals
Connector J1 ____________ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __4
Disassembly
Reassembly______________________ __ __ __ __ __ __ __ __ __ __ __ __7
Changing the Circuit Board _________________________________7
Fault Finding and Alignment
Sequence of Adjustments
____________ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __6
____________ ______________ ____4
____________ ______________8
____________ ______________ __9
3
SERVICE: Telephone
Connectors and Signals
The location of the logic board connectors and a description of the respective
signal names will follow below.
Connector J1
1 ATMS
2 PWSRC
3 LSPCTRL
4 AGND
5 AFMS
6 SWDC5
7 ICTRL
8 DGND
9 VPPFLASH
10 HOOK
11 DTMS
12 DFMS
13 ONSRQ
14 DCIN
SM1341EN/CONJ1.GEM
Table 1: Connector J1
Pin Signal In/Out Function
1 ATMS In Audio To Mobile Station
Sensitivity: 50 mV,
referred to +/-2.3 kHz dev.
Input imp. 10 kΩ/ nF
2 PWRSRC In Power source
Indicates external power supply
Log. "1": External po wer supply
Log. "0": Battery
3 LSPCTRL Out Loudspeaker control
Handsfree loudspeaker control
Log. "1": Speaker ON
Log. "0": Speaker OFF
4 AGND Analog ground
Signal ground 0 V
Return lead for pi n s 5 an d 1
4
Pin Signal In/Out Function
SERVICE: Telephone
5
6
7
8
9
10
AFMS
SWDC5
ICTRL
DGND
VPPFLASH
HOOK
Out Audio From Mobile Station
Output 307 mV, referred to 5.7 kHz dev.
(varies with volume)
Output imp. < 1 k
Out Logic control signal (4.8 V) for external
units.
Max. current 10 mA
Out Control of external supply current.
Log. "1": Supply 700 mA
Log. "0": Supply 30 mA
Digital ground
In Disconnects internal watchdog during
test and supplies programming voltage to
flash memory
Open: normal mode
5 V: test mode
12V: programming voltage
In External Handsfree present
Log. "1": External HF present
Log. "0": No external Handsfree
Ω
11
12
13
14
DTMS
DFMS
ONSRQ
DCIN
In Data To Mobile Station
Asynchrono u s se ria l tr an sf er :
8 bits, 600 bits/s
Input impedance 100 kΩ/ nF
Log. "1": 4.8 V
Log. "0": 0.5 V
Out Data From Mobile Station
Asynchrono u s se ria l tr an sf er :
8 bits, 600 bits/s
Log. "1": 4.8 V
Log. "0": 0.5 V
In ON and Service Request signal
If momentarily connected to GND causes
telephone to shift between ON and OFF
state
In Supply to telephone
Min. 5.3 V; max. 8.5 V
Nominal 6.8 V, max. 1 A
5
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