background image

Disassembly

A complete disassembly of the telephone is described below.

1. Remove the battery and the antenna.

Before opening the unit for further disassembly, be sure the parts can be
placed on a dust-free and grounded surface. It is also important that you avoid
touching any contact points and the display
 with your fingers.

2. Place the telephone on its front and remove four screws (4 and 6) with the

appropriate torque screwdriver.

3. Place the telephone on its back and remove the front cover (1), lifting it

upwards.

4. Remove the keypad (15).

5. Taking care not to bend the contact pins, remove the earpiece by lifting it

upwards.

6. Move the two clips (9) at the sides of the frame outwards from the board.

7. Carefully lift the board at the edges of the lower part upwards approximately

1 cm. Free the upper part of the board from the upper clip, twisting the board
without moving it upwards. Carefully lift the board upwards from the frame,
after it has got clear of the upper clip.

2

3

5

4

6

8

7

9

18

10

12

13

14

15

17

16

1

11

SERVICE: Telephone

6

Summary of Contents for 1341-B

Page 1: ...SERVICE Telephone Ericsson Handheld Telephone 1341 B ...

Page 2: ...SERVICE Telephone 2 ...

Page 3: ...________4 Disassembly __________________________________________6 Reassembly______________________________________________7 Changing the Circuit Board _________________________________7 Fault Finding and Alignment__________________________8 Sequence of Adjustments ____________________________9 SERVICE Telephone 3 ...

Page 4: ...d to 2 3 kHz dev Input imp 10 kΩ nF 2 PWRSRC In Power source Indicates external power supply Log 1 External power 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 pins 5 and 1 SM1341EN CONJ1 GEM 1 ATMS 2 PWSRC 3 LSPCTRL 4 AGND 5 AFMS 6 SWDC5 7 ICTRL 8 DGND 9 VPPFLASH 10 HOO...

Page 5: ...lash memory Open normal mode 5 V test mode 12V programming voltage 10 HOOK In External Handsfree present Log 1 External HF present Log 0 No external Handsfree 11 DTMS In Data To Mobile Station Asynchronous serial transfer 8 bits 600 bits s Input impedance 100 kΩ nF Log 1 4 8 V Log 0 0 5 V 12 DFMS Out Data From Mobile Station Asynchronous serial transfer 8 bits 600 bits s Log 1 4 8 V Log 0 0 5 V 13...

Page 6: ...ue screwdriver 3 Place the telephone on its back and remove the front cover 1 lifting it upwards 4 Remove the keypad 15 5 Taking care not to bend the contact pins remove the earpiece by lifting it upwards 6 Move the two clips 9 at the sides of the frame outwards from the board 7 Carefully lift the board at the edges of the lower part upwards approximately 1 cm Free the upper part of the board from...

Page 7: ...ver the board 4 Place the earpiece in its position 5 Place the keypad on the light conductor 6 Carefully replace the front cover 7 Place the telephone on its front 8 Tighten the screws diagonally as shown in torquing sequence below It is of utmost importance that the screws are tightened to 0 20 Nm with a dynamometric screwdriver Changing the Circuit Board 1 Transfer the EEPROM contents to the per...

Page 8: ...is found in the section Connectors and Signals There you will also find illustrations showing the distribution of signals on the respective connector pins The telephone is to be tested with the following settings if nothing else is ex plicitly stated DC power supplied either via battery connector 6 8 V or system connector 6 8 V Channel 1 RX 935 0125 MHz TX 890 0125 MHz TX power Test program option...

Page 9: ...frequency at antenna connector Value 890 0125 MHz Tolerance 2 2 kHz Procedure If the transmitter frequency is not within 890 0103 890 0147 MHz use test option 18 and press M 0 to calibrate the VCTCXO automat ically When the calibration is done the new stored value will be displayed Note Prior to an automatic calibration test 15 must be set to its default value 1 normal operation Alternatively the ...

Page 10: ...asurement point None Value None Tolerance None Procedure Enter test option 9 and press M S and the stored reference value for the RSSI indication will be displayed If an alarm signal is heard the error of the received frequency is greater than 1 kHz and further calibration cannot be done Increase the signal strength to 60 dBm and press M S Change the RF in signal to 935 0175 MHz 5 kHz wait 5 secon...

Page 11: ...Bm 7 6 5 dBm Tolerance 2 4 dBm at all power levels Procedure If the transmitter output power is not within the above stated lim its use test option 5 and press either 0 1 or 2 to select power table The dis play will show selected table power level and current voltage value Use the and buttons to adjust the output power Press M S to store the value or M to step to the next power level When all powe...

Page 12: ...e deviation Press M S to store the new value Item 5 Nominal Deviation Purpose Check and if necessary adjustment of the maximum deviation from the transmitter Input signal 1 kHz tone with a level of 307 mVRMS at the ATMS input on the service adapter Test method Radio test set in TX mode measured with a deviation meter Test program settings 1 1 Channel selection 2 2 TX On at Power Level 2 27 0 Selec...

Page 13: ... 2 TX On at Power Level 2 20 0 Audio paths muted 22 0 Generate 5970 Hz signal 22 1 Generate 6000 Hz signal 22 2 Generate 6030 Hz signal 22 4 SAT switch unmuted Note For cellular tests use 15 kHz LP filter Measurement point At the antenna connector Value 1 7 kHz Tolerance 10 Procedure If the transmitter deviation is not within 1 53 1 87 kHz use test option 22 and press M Use the and buttons to adju...

Page 14: ...e measured with a deviation meter Test program settings 1 1 Channel selection 2 2 TX On at Power Level 2 20 0 Audio paths muted 23 1 Generate one s Measurement point At the antenna connector Value 6 4 kHz Tolerance 10 Procedure If the transmitter deviation is not within 5 8 7 0 kHz use test op tion 23 and press M Use the and buttons to adjust the deviation Press M S to store the new value SERVICE ...

Page 15: ...press M Use the and buttons to ad just the level Press M S to store the new value Check the harmonic distortion on the AFMS signal Not to exceed 5 Check that the receiver sensitivity is 20 dB SINAD P with an RF signal of 113 dBm Item 9 Current Purpose To calibrate the current consumption of the telephone Input signal 6 0 VDC via the system connector Test method Measured with a DC current meter Tes...

Page 16: ...SERVICE Telephone 16 ...

Reviews: