SwissPhone DE10A User manual

Service Manual DE10A (DE935) Page 1 / 21
Swissphone
Service Manual DE10A (DE935)
Version 1.2, February 2012
Swissphone Telecom AG
Fälmisstrasse 21
CH-8833 Samstagern

Service Manual DE10A (DE935) Page 2 / 21
Contents
1Document .................................................................................................................................... 3
1.1Purpose .................................................................................................................................. 3
1.2Abbreviations and terms ........................................................................................................ 3
1.3References ............................................................................................................................. 3
2Assembly/disassembly information......................................................................................... 4
2.1Assembly................................................................................................................................ 4
2.1.1Preparation ............................................................................................................................ 4
2.1.2Assembling the device........................................................................................................... 4
2.2Disassembly........................................................................................................................... 5
2.3Separating the Display from the Main Board ......................................................................... 6
3Modes of operation..................................................................................................................... 6
3.1Normal mode.......................................................................................................................... 6
3.1.1Additional information on ECO mode .................................................................................... 6
3.2Hidden menu.......................................................................................................................... 6
3.2.1Device information................................................................................................................. 6
3.2.2Delete all messages .............................................................................................................. 6
3.2.3Delete IDEA keys .................................................................................................................. 7
3.2.4back ....................................................................................................................................... 7
3.3Test mode .............................................................................................................................. 7
3.3.1Test POCSAG ....................................................................................................................... 7
3.3.2Test LCD................................................................................................................................ 8
3.3.3back ....................................................................................................................................... 8
4Instructions on adjustment to the tuning frequency.............................................................. 9
4.1Requirements......................................................................................................................... 9
4.2Retuning ................................................................................................................................. 9
4.2.1Measurement setup............................................................................................................... 9
4.2.2Preparing the pager for the tuning frequency...................................................................... 10
4.2.3Settings................................................................................................................................ 10
4.2.4HF adjustment ..................................................................................................................... 10
4.3Sensitivity test ...................................................................................................................... 11
5Changing the channel spacing ............................................................................................... 11
6Changing the frequency band................................................................................................. 11
7Function test/calibration.......................................................................................................... 12
7.1Measurement setup ............................................................................................................. 12
7.2PSWplus tools (service) ....................................................................................................... 12
7.3Service tools in PSWplus (service) ...................................................................................... 15
7.3.1Power Source ...................................................................................................................... 15
7.3.2RSSI calibration................................................................................................................... 16
7.3.3Repair number..................................................................................................................... 17
8Measurements........................................................................................................................... 17
8.1BAT+ .................................................................................................................................... 17
8.2VDD...................................................................................................................................... 17
8.3Batt measurement correction ............................................................................................... 17
8.4Sub clock.............................................................................................................................. 17
8.5Main clock normal ................................................................................................................ 17
8.6Main clock shift..................................................................................................................... 18
8.7PLL reference oscillator ....................................................................................................... 18
8.8V+......................................................................................................................................... 18
8.9Tune and test VCO .............................................................................................................. 18
8.10T1/T2 current (LNA) ............................................................................................................. 19
8.11T41 current (VCO)................................................................................................................ 19
8.12T80 current (buffer) .............................................................................................................. 19
8.13T51 current (1st mixer)......................................................................................................... 19
8.14IF current (IC61)................................................................................................................... 19
8.15HF current ............................................................................................................................ 19
8.16µC on current ....................................................................................................................... 20
8.17Off mode current .................................................................................................................. 20
9List of testing points ................................................................................................................ 21

Service Manual DE10A (DE935) Page 3 / 21
1 Document
Version Date Author Subject
1.0 May 2011 D. Widmer 1s
t
version created on the basis of DV09A and DE920
1.1 02.11.2011 D. Widmer Minor corr.; name of end device changed to DE935
1.2 23.02.2012 D. Widmer Limit values in Section 8 updated
1.1 Purpose
This manual contains all the information required to perform service work on the DE935, such as
adjusting the tuning frequency, checking the function of individual circuit blocks, detailed
measurements etc. DE935 usually refers to the end device, whereas the name DE10A is generally
used for the project and the device’s components.
1.2 Abbreviations and terms
Ah Ampere-hours
HF High Frequency
IF Intermediate Frequency
LF Low Frequency (audio)
LNA Low Noise Amplifier
PLL Phase Locked Loop
VCO Voltage Controlled Oscillator
np not populated
nc not connected
POCSAG Paging format (Post Office Code Standardization Advisory Group)
ppm parts per million
PWM Pulse Width Modulation
RIC Receiver Identity Code
RSSI Received Signal Strength Indication
PSW Parameterisation SoftWare
PWM Pulse Width Modulation
TEM cell Transverse Electro Magnetic cell
AC Alternating Current
µC µ(micro) Controller
Signal description
{/Signalname} Signal Low active e.g.: /RST_LCD
{Signalname} Signal High active LE_PLL
Component references
Component reference pin number e.g.: IC101.6
1.3 References
[1] TPH DE10A Rev1.0 visiert.doc
[2] Schematic drawing DE10A VHF: 0434.2061
[3] Component assignment plans DE10A VHF: 0434.2005 and 0434.2006

Service Manual DE10A (DE935) Page 4 / 21
2 Assembly/disassembly information
Putting the casing together requires special care and attention otherwise the ribbon cable of the liquid
crystal display could be damaged. Assembly is therefore described first. Opening the casing is
described in the second part of this document.
2.1 Assembly
2.1.1 Preparation
To simplify the assembly process it is advisable to affix a self-adhesive tab (0319'591 label) to the
ribbon cable. This tab helps to keep the cable in the correct position and ensures that the cable is not
crushed unintentionally. The drawings on the next page show where the tab is to be affixed. It is
marked in red.
Both casing sections contain components that are not affixed with screws, the keypad (1) in the upper
section of the casing and the vibrator (2) in the lower section of the casing. Both components must be
affixed correctly before the device is assembled. The vibrator is fitted with the flyweight (3) pointing
outwards. The keypad easily falls out during assembly and therefore has to be pushed slightly into the
upper section of the casing on the studs.
2.1.2 Assembling the device
To assemble the DE935, set the main circuit board with the clear plastic light guide and liquid crystal
display circuit board in the lower housing part (4) place the subrack with light conductor and the
subrack of the liquid crystal display in the lower casing section (4) and snap the upper section into
place. Make sure that you start from the side with the beeper in order that the beeper seal is not
pushed out of place. This sequence is necessary as the flex from the subrack of the liquid crystal
display tends to run outside of the middle tab of the five fixing tabs (5), which can result in damage.
Please always check that the flex is on the correct side of the middle tab.
The two sections of the casing are then screwed together using two screws (no. 0 Philips screwdriver).
Position of the self-adhesive tab (Section 0).
1
2 and 3
4
5

Service Manual DE10A (DE935) Page 5 / 21
2.2 Disassembly
First, remove the battery and undo the two screws. Then carefully lift the device on the side with the
screws in order to release the tabs snapped in place on the opposite side. No components are affixed
with screws inside the device.
Place the pager on the table with the display facing downwards
Separate the two casing sections by a few millimetres on the battery side
Carefully separate the two casing sections on the ribbon cable side. The upper casing section
must not be pivoted too much otherwise the ribbon cable may become damaged by a tab.
Check that the ribbon cable has not been damaged.

Service Manual DE10A (DE935) Page 6 / 21
2.3 Separating the Display from the Main Board
After the SMD connector has been opened and the flex has been disconnected, the clear plastic light
guide clamp (next to the flex connector) must be carefully released. Then, the same side of the clear
plastic light guide is raised until the fixing studs are lifted out of the PCB; the clear plastic light guide
can then be removed to the side.
Note: Do not use excessive force when disconnecting the clear plastic light guide from the
circuit board, otherwise the guide angle of the clear plastic light guide may break.
The PCB and the clear plastic light guide are assembled in reverse order – put in position first, then
snap into place and then connect the flex. The flex can be bent slightly in the hand to make it easier to
carry out the work.
3 Modes of operation
3.1 Normal mode
When a battery is inserted into the DE935 or when the confirmation button is pressed and held down
while the pager is switched off the pager switches on and runs in normal mode.
This is the standard mode of operation. Please read the manual for information on the corresponding
device functions.
3.1.1 Additional information on ECO mode
This is a special mode which is part of normal mode. It facilitates improvement of the device’s
autonomy (battery life) as well as a slight improvement in sensitivity. The improvements are achieved
by switching off the display including drivers. The clock and the icons become visible again after a
button has been pressed.
Eco mode can be activated/deactivated via the Settings menu item (if configured).
This mode must not be confused with “Radio” = eco. The receiver (Radio) is constantly activated and
deactivated during normal mode (Economizer) in order to provide greater battery autonomy.
3.2 Hidden menu
If all three buttons are pressed and held down when the battery is inserted the hidden menu appears.
The menu items can be selected using the navigation buttons and executed using the confirmation
button.
3.2.1 Device information
Shows the firmware version and the serial number of the device. Return to the hidden menu using the
confirmation button.
3.2.2 Delete all messages
Deletes all messages in the pager after the query has been confirmed.

Service Manual DE10A (DE935) Page 7 / 21
3.2.3 Delete IDEA keys
All IDEA keys are deleted after confirmation.
3.2.4 back
Returns to the pager’s normal mode of operation.
3.3 Test mode
If the two navigation buttons are pressed and held down while the battery is being inserted the test
menu appears. The menu items can be selected using the navigation buttons and executed using the
confirmation button. The test mode main menu appears as follows.
3.3.1 Test POCSAG
3 modes can be set – tuning mode, verify mode and free mode.
tuning mode verify mode free mode
tuning mode
In tuning mode, HF is permanently set to the tuning frequency and the device can be adjusted as
described in Section 4.2. The parameters cannot be changed in this mode.
verify mode
In verify mode, the pager can be checked on the customer frequency or on one of the 8 customer
frequencies (depending on whether it is a single-channel or multi-channel device). The tuning
frequency and the band limits can also be selected. A short alert is signalled when a call is received;
call suppression is not enabled.
The parameters are as follows in verify mode. "Network" is network 1 (can be changed), "RIC" =
programmed and "Radio" = economized.

Service Manual DE10A (DE935) Page 8 / 21
free mode
free mode is available for individual tests in addition to the two main modes. All the parameters in free
mode can be selected as follows.
Network: tuning / upper / network 1 / network 2 / network … / network 8 / scanner / lower
Baud: auto / 512 / 1200 / 2400
Radio: economized / off / continuous
RIC: 500 A / programmed
Monitor: off / on
Network
network 1 to 8: Frequency is between the lower and upper frequency
scanner: Network 1 and network 2 are scanned
lower: Frequency at lower end of band
tuning: Tuning frequency (average frequency)
upper: Frequency at upper end of band
Baud
Auto Uses the baud rate in the configuration
512 / 1200 / 2400 Uses the selected value
Radio
economized HF runs in economizer mode (standard operating mode)
off HF is always off (no reception possible)
continuous HF is always on
RIC
500 A Evaluates calls with RIC 500, subaddress A
programmed Evaluates calls with RIC from the configuration
Monitor
off Normal mode, traffic not audible
on Directs the data to the beeper (traffic audible in basic band)
3.3.2 Test LCD
With Test LCD, you can scroll between the following test displays using the navigation buttons.
Return to the test menu using the confirmation button.
3.3.3 back
Exits test mode and starts the pager in normal mode after a reset.

Service Manual DE10A (DE935) Page 9 / 21
4 Instructions on adjustment to the tuning frequency
4.1 Requirements
The tuning frequency must be in the middle of the frequency band that the device was set up for at the
factory. It is not advisable to change the tuning frequency.
4.2 Retuning
4.2.1 Measurement setup
Cathode ray oscilloscope
Frequency counter
HF generator
Test cable TK9xx, item no. 0951005 (see illustration)
Multimeter
Pocsag sensor
The IF cable is connected to a CO with frequency counter and the HF cable is connected to a signal
generator. The two sprung metal pins establish a contact at TP61 and TP62.
HF cable IF cable (450kHz)
TK9xx
(rearview)
HF generator
CO
Freq. counter
DE935

Service Manual DE10A (DE935) Page 10 / 21
4.2.2 Preparing the pager for the tuning frequency
Remove the battery cover and the battery
Remove the tuning compartment cover (black cover plate). Note: Seal will be destroyed
Insert the battery and put the device in test mode: hold both scroll buttons down while the battery
is being inserted until the inverted start screen appears on the display
Press the Enter button to select "Test POCSAG" from the test menu
"Mode tuning" will be displayed in the top line. If not, scroll through the test modes using the Enter
button until "Mode tuning" is displayed
Connect test cable TK9xx to the device
4.2.3 Settings
HF generator: fHF = tuning frequency
Deviation = 4.5 kHz
HF level: Must be continuously reduced during adjustment
CO: Time / DIV: 0.5 ms
V / DIV: 20 mV
4.2.4 HF adjustment
The HF level must be reduced gradually during adjustment. It must be clearly above the noise limit
and the receiver must never be allowed to fall within the limits. This is identified if the IF amplitude
remains unchanged despite an increase in the HF level. Execute the following steps to tune the
receiver.
1. With C40, tune the VCO control voltage (measured at TP3) to 1.50 V ± 0.05 V and check the
voltage at the band limits to ensure that they comply with the limit values (see Section 8.9).
2. With C2, (antenna circuit) tune to the maximum IF signal amplitude.
3. With C14, adjust to the maximum IF signal amplitude (tune band-pass).
4. With C11, adjust to the maximum IF signal amplitude.
5.
6. With C11, C14, C2 (in this order) maximise the IF amplitude again (fine adjustment).
7.
Adjust VCO control
voltage (measured at
TP3) with C40 Tune band-pass with C14
Tune antenna with C2
Tune band-pass with C11
4
1
3
5
6
2 7