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Programmes After Market Services (P.A.M.S.)
Technical Documentation
NME­2A SeriesTransceivers




Troubleshooting
Instructions




Original 08/97
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation




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P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



Contents

Page No
Troubleshooting Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
BB Troubleshooting Flow Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Flash Programming OK; part 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Flash Programming OK; part 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Flash Programming OK; part 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Flash Programming OK; part 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
PWR Button Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Display Selftest Failed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
No Registration to the System (no serv) . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Audio Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
RF Troubleshooting Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
RX Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
TX Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
UHF Synthesizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
VHF Synthesizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19




Original 08/97 Page 3
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation




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P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



Troubleshooting Instructions
The purpose is to define fault block of the module and then find out the
broken component. The trouble shooting diagram has been planned so
that the fault, whatever it is, can be found by as simple measurements as
possible.
Required servicing equipment:
­ PC for PCLocals
­ Power supply (12 V 5 A)
­ Digital multimeter
­ Oscilloscope with 10:1 probes
­ Spectrum analyzer (capable of 10 W input e.g. external attenuator)
­ Signal generator
­ Test SIM
­ RF cables with BNC or N in the other end
­ Modular cable
­ RS232/M2BUS adapter DAU­2
­ HP8922H

BB Troubleshooting Flow Diagrams
The baseband flow diagrams give you the overview of the blocks. The
purpose is that you proceed through the flow diagram so that, if your
answer is YES for the asked question, go straight to the next level, but if
your answer is NO, you have to go the sub­branch.




Original 08/97 Page 5
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation



Flash Programming OK; part 1


FLASH programming OK




MBUS YES Display: NO D250/MCU/pin 3
registration selftest failed D300/ASIC/pin 97
OK? rstrobe
YES

3

NO Short circuits in data
Power YES Display: data lines. data line
stays on? selftest failed disconnected, VREF
unconnected
NO YES
NO
VBATT If D250 at
Check X102 pins 4, 16 ? NO NO pin 66/TXD
MBUS line X100/5 R263
+ 5 V? doesn't apply
+5 V after pwr on? +5 V change
YES D250
YES
NO YES
N100/pin 8/XRESET NO Check
C114 OK? V250 base R262, R263
+5 V after pwr on?
1 V V250, V251
YES
YES
R106 OK?
Check R257
YES R260, R258,
V250, R268,
R270
Change N100
YES
MCU/D250/PIN67/RDX Change first
+5 V after pwr on ? D250


NO
If R259 is OK
change D250

YES
Power supp. to the logic
circuits +5 V after pwr on? 2

NO
Change N100




Page 6 Original 08/97
P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



Flash Programming OK; part 2


2


NO MCU/D250/pin 10 YES
RESETX +5 V after
power on?




YES 26 MHz at MCU NO
26 MHz clock Change D300
Change D300 D300/pin 119? /D250 pin 69
/MCUCLK?

NO YES

Check components
D301, D302, C306 MCU/D250 NO
/pin 8/MD2, Check joints
R913, G902, C918 and foils
/pin 9/STNDBY?

YES


MCU/D250/pin 43 NO
/XPWROFF pulses up to Change D250
+5 V after pwr on?

YES


MCU/D250/pin 77 NO
/IRQ0 +5 V after Change D300
power on?

YES


MCU/D250/pin 4 NO
/WSTROBEX +5 V Check D300
after pwr on?

YES

Check all soldered joints
The data and address signals must
a clear difference between low (0 V)
and high (+5 V)




Original 08/97 Page 7
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation



Flash Programming OK; part 3

3


MBUS registration OK?

YES

Display: selftest failed?

YES

EEPROM YES
initialization OK?
(FLASH8N.MES)
4

NO


NO D253/EEPROM
Check D300 /pin 27/EROMSELX pulses
+5 to 0 V during r/w
action?

YES


NO D253/EEPROM
Check D250 /pin 1/RSTROBEX pulses
(D300) +5 to 0 V during r/w
action?

YES


NO D253/EEPROM
Check D250 /pin 1/WSTROBEX pulses
(D300) +5 to 0 V during r/w
action?

YES

Change D253




Page 8 Original 08/97
P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



Flash Programming OK; part 4

4



D251/FLASH NO Check X100/pin 14
/pin 11 +12 V during R271, L250, R264
programming? R265, C264

YES

D250/MCU NO Check X100/pin 6
/pin 64/RXD2 pulses R252, R253, R255
during programming? C254

YES

X100/pin 7
/TXD2 pulses during NO Check D250/pin 63
programming? R250, R251, C250


YES

D251/FLASH NO
/pin 12/PWD +5 V Check D300
after power on?

YES

D251/FLASH NO
/pin 9/ROMSELX pulses Check D250 (D300)
from +5 to 0 V after
power on?
YES

D251/FLASH NO
/pin 37/RSTROBEX pulses Check D250 (D300)
from +5 to 0 V after
power on?


Check D251/FLASH
ADDRESS/DATA LINES YES D251/FLASH NO
/no shortcircuits or /pin 38/WSTROBEX pulses Check D250 (D300)
unconnected pins allowed from +5 to 0 V after
power on?
OK
Change D251




Original 08/97 Page 9
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation



PWR Button Fault


Nothing happends
when PWR button Check N101 pin 2
is pressed
+6.2 V if not OK
change N101

NO

N100/PSL pins NO
5,20 +6.2 V When either N101/pin 4
XPWRON is low or VBATT voltage
Check V106, L100 IGNS is high
Change N100
YES Check
NO YES
V102, V103,
NO V104, R109,
N100/PSL V110 gate R110, R111,
D250/pin 5,42 VL1 NO pin 9/XPWROFF pulses is 0V R113, R133,
+5 V When XPWRON R134, C100
from 0 to +5 V after C112, C124
is push high power on YES R143, V107
R100, R124
YES
YES Check V101
if OK change V110
Check D250, Check VL1, VL2, VA2, VREF
D300 if OK then change N100




Page 10 Original 08/97
P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



Display Selftest Failed


Display selftest failed or
phone doesn't registrate to
the system (tester)



Use PCLocals to
find out a reason




MCU internal test Unprogrammed FLASH
YES Unconnected pins in MCU
MCU RAM bus test
MCU ROM bus test address or data lines
MCU IMEI test

NO
DSP clock oscillator
DSP pin 45/INT1
MCU DSP code YES DSP pin 10/ERAMHI
download: failed, DSP pin 9/IOX
DSP tests: no responce DSP pin 12/EROM
RFI bus fault DSP pin 14/RWN
DSP pin 15/EXM
NO DSP pin 39/RSTB
RFI/RFIAD 3:0
RFI/RFIDA 11:0
RFI pin 49/RDX
RFI pin 50/WRX
MCU audio codec RFI pin 53/RFICLK
test: failed RFI pin 59/RFI2CLK
DSP RAM D201, D202
DSP/DSPDA
YES DSP/DSPAD

Codec N150/pin 12: PCMDO
Codec N150/pin 13: PCMDI
Codec N150/pin 19: PCMCLK
Codec N150/pin 20: XSELPCMC




Original 08/97 Page 11
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation



No Registration to the System (no serv)

No registration to the
system (no svc)
no call




Selftest OK


YES
DSP pin 43, 45 INT0, 1 (from ASIC)
RFI pins 1,63/RXI, RXQ
RFI pin 3/EXTBG (4.096 V)
RFI pin 4/VCM (2.35 V)
RFI pin 6/TXC (to RF)
RFI pins 8,9/TXQ+, TXQ­ (to RF)
RFI pins 11,12/TXI+, TXI­ (to RF)
RFI pin 14/AFC (to RF)
RFI pins 20...23,28,29/PDATA 5:0
RFI pin 51/DAX (to ASIC)
ASIC/D300/pin 105/SYNTHPWR (to RF)
ASIC/D300/pin 104/TXP (to RF)
ASIC/D300/pin 106/TXPPWR (to RF)
ASIC/D300/pin 111/SENAT (to RF)
ASIC/D300/pin 112/SENAR (to RF)
ASIC/D300/pin 113/SDAT (to RF)
ASIC/D300/pin 114/SCLK (to RF)




Page 12 Original 08/97
P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



Audio Fault

Audio fault
Microphone or earphone
signal missing




CODEC pin 15/SYNC (from ASIC)
Microphone and YES CODEC pin 16/CODEC_CLK (from ASIC)
earphone signal DSP pins 79, 82/PCMCOSYCLKX (from ASIC)
missing? DSP pins 60, 81/PCMDATRCLKX (from ASIC)
DSP pin 80/CODEC_CLK

NO



Microphone signal YES CODEC pin 21/HF_MIC
missing? CODEC pin 22/MIC
CODEC pin 10/PCMOUT

NO


CODEC pins 6, 7/LSP
Earphone signal YES CODEC pins 3, 4/EAR
missing? CODEC pin 14/PCMIN
DSP D200/pin 78




Original 08/97 Page 13
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation



RF Troubleshooting Instructions
The RF part consist of RX, TX and synthesizers as main blocks.
Interface to the rest of the radio is mainly through RFI.
In normal use, in the network, it is not possible to localize a malfunction to
any of these parts alone, because all of them may be needed to operate
the radio.
With a GSM tester like HP8922G/H it is possible to operate the radio in a
simple network like manner, and in that way localize some faults,
especially when you monitor the radio with PCLocals at the same time.
If the fault means, that the radio does not work with HP8922G/H then it is
possible via PCLocals in local mode, to operate the parts individually, and
in that way see if the parts can do what they are supposed to. It is also
possible to operate the parts dynamic, to check the switching between the
different modes, and that is more or less sufficient to tell if the RF is OK or
not.
The following descriptions all starts with a simple and top level check. If
that fails or if the radio still has a malfunction, then the checks goes
deeper and deeper into the circuits to help finding the circuit that is
responsible for the malfunction.
RX Part

1. RSSI calibration (Input ­57 dBm, channel 60, 947.06771MHz):
Checks the signal path from antenna to RFI and the AGC. The RFI
operates only as level detector in this mode. The offset value is a measure
of the total gain in the RX.
­ ­37 < Offset < 49 dB
­ Calibration values between ±2 dB
­ If it is OK, go to 2.
­ If it fails then select via PCLocals RF control, Active unit RX, Operation
mode continuous, Continuous mode channel 60, AGC 93. Input ­57
dBm 947.06771 MHz.

Measure with probe and oscilloscope or with the probe and spectrum
analyzer.
Note: When measuring levels with an oscilloscope probe to the
spectrum analyzer, some calibration is needed!




Page 14 Original 08/97
P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



1.1. Check 13 MHz signal:
­ RXI and RXQ > 0.3 VPP at 12.93 MHz.
­ J702 input to 13 MHz filter > 0.5 VPP
­ Check RXPWR J705 = 5 ±0.1 V
­ Check 8.5 RX TX SW J703 = 7.7 ±0.1 V

1.2. Check 71/13 MHz mixer:
­ N701, 71/13 MHz mixer: pin 15 4.8 ±0.2 V
­ Enable: pin 21 > 4 V
­ AGC5: <0.5 V (<2.5 V in burst)
­ Output: J702 2.75 ±0.1 V
­ LO: pin 6 >­10 dBm, 232 MHz

1.3. Check 71 MHz signal:
­ AGC1 to AGC4 low (AGC4<2.5 V in burst)
­ N702: pin1 and pin14 4.8 V ±0.2 V
­ Enable: pin 6 >4 V
­ Input: pin12, 13 ­50 dBm, 71 MHz
­ Output: pin 4, 5 ­10 dBm, 71 MHz

1.4. Check UHF mixer:
­ LO C934: +9 dBm ±3 dB, 1014 MHz
­ Signal in C722: ­50 dBm, 947.07 MHz (­57 dBm input)
­ Signal in C722: ­30 dBm, 947.07 MHz (­37 dBm input)
­ Signal out C726: ­57 dBm, 70.93 MHz

1.5. Check 71 MHz amp:
­ Output to filter: ­35 dBm, 70.93 MHz

2. AFC (Input ­57 dBm, channel 60, 947.06771MHz):
Checks the signal path, the VCXO and some parts of the demodulator.
The VCXO is tuned high, mid and low while the frequency deviation is
measured.
­ 10 kHz < High < 20 kHz
­ ­5 kHz < Mid < 5 kHz
­ ­20 kHz < Low < ­10 kHz




Original 08/97 Page 15
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation


2.1. Check the VCXO:

After AFC is done, the tuning voltage will stay high.
In other modes the tuning voltage will be in mid.
­ Measure at J902: > 3 VPP
­ High tuning: freq = 26 MHz +400 Hz ±100 Hz
­ Low tuning: freq = 26 MHz ­400 Hz ±100 Hz
­ Mid tuning: freq = 26 MHz ±50 Hz

2.2. Check burst mode:
Select via PCLocals RF control, Active unit RX, Operation mode burst,
Continuous mode channel 60, AGC 93. Input ­57 dBm 947.06771 MHz.
AGC is in that mode internally controlled.
Measure with scope ac coupled on RXI and RXQ, the output to RFI. Trig
the scope on RXPWR or 8.5RX TX SW or AGC0.
­ Signal should be about 30 mVPP, and vary as the AGC operates.
­ If not check the signal path and the LO signals as above.

3. Noise and sensitivity:
Checks the overall RX performance, except real demodulation.
Use F2 to measure clipping level and difference between I­Q.
Disconnect or switch off the RF signal from the generator.
Use F3 to measure SNR and Sensitivity.
­ Clipping + SNR >50
­ SNR > 20
­ Sensitivity < ­103 dBm
­ I­Q < 1 dB
­ If not repeat from 1 again.

4. Check camp on to HP8922G/H:

Set HP8922G/H up with neighbors for its own BCCH and some empty and
some used channels. In cph use 3, 5, 20 (=own BCCH), 59 and 90.
Use PCLocals F8 to monitor the radio.
­ RXlevel within ±2 dB from the BCCH level.
­ RXlevel for empty neighbors less than 3.
­ Decoding of the information in the used neighbors
­ If not OK, the malfunction may be in the RFI and the circuits that con-
trol the RFI.


Page 16 Original 08/97
P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



TX Part

1. Check burst output:

Via PCLocals select local mode, RF control, TX mode, Power level 10
(23 dBm), Operation mode burst, Data type random, Continuous mode
channel 60, Channel 60, Monitoring channel 1.
Measure with spectrum analyzer on the antenna connector (40 dBm max
signal needs an external attenuator), and with scope on the power amps
control input pin 2.
­ The output burst should have peak amplitude at 23 dBm ±3 dB, and
center at 902 MHz.
­ If it is OK, check at higher and lower levels, up to level 2 (39 dBm) and
down to level 15 (13 dBm).

1.1. Check power tuning:

Via PCLocals select local mode, Power tuning.
­ Coefficients from 0.8 at level 2 to about 0.1 at level 15.
­ Tolerance of ±0.1 at level 2 to ±0.050 at level 15.
­ The control signal should follow the RF amplitude with a maximum of 4
to 6 V at level 2 and 2 to 2.5 V at level 15.

1.2. TX buffer and level regulator:

Via PCLocals select local mode, RF control, TX mode, Power level 10
(23 dBm), Operation mode burst, Data type random, Continuous mode
channel 60, Channel 60, Monitoring channel 1.
Measure with spectrum analyzer on the antenna connector (40dBm max
signal needs an external attenuator), and with scope on the power amps
control input pin 2.
­ If control signal goes up and RF does not follow, check with a probe
the RF input to the power amp at pin 1. It should be at 3 to 5 dBm.
­ Follow the RF signal back to see if it is at the output of the balun T802.
­ When measuring before the power amplifier continuous mode is pos-
sible.




Original 08/97 Page 17
P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation


1.3. Modulator and LO signal generation:

Via PCLocals select local mode, RF control, TX mode, Power level 10
(23 dBm), Operation mode continuous or burst, Data type random,
Continuous mode channel 60, Channel 60, Monitoring channel 1.
Measure with oscilloscope probe and spectrum analyzer.
­ Output of modulator on T802: ­10 dBm ±5 dB.
­ Input to the modulator consist of three discrete frequencies, where the
wanted is the lowest frequency, and at a level about 15 dB higher than
the other two. Absolute level about ­10 dBm for the wanted signal.
­ Check the LO generating mixer (UHF TX and VHF RX PLL), the ampli-
fier and the filter.
­ UHF LO: 5 dBm ±5 dB, 1014 MHz
­ VHF RX PLL: ­5 dBm ±5 dB, 116 MHz
­ Check the modulating input, balanced pairwise for I and Q, about 1
Vpp for every signal, d.c. at 2.4 V.
­ Check the power and enable to the modulator.
­ Check the UHF and VHF synthesizers.

2. Modulation spectrum:
Select I and Q TUNING in PCLocals. Measure with spectrum analyzer on
the antenna connector (up to 40 dBm output!). Span 0.2 MHz, resolution
BW 10 kHz, video 10 kHz, sweep time 0.5 sec.
­ Relative to the mainslope the signal at +67 kHz should be more than
30 dB down, and the signal at +135 kHz should be more than 50 dB
down.
­ If not tune the offset values, I and Q d.c. offset to change the signal at
+67 kHz, phase and amplitude offset to change the signal at
+135 kHz.




Page 18 Original 08/97
P.A.M.S. NME­2A
Technical Documentation Troubleshooting Instructions



UHF Synthesizer

Via PCLocals select local mode, RF control, TX mode, Power level 10
(23 dBm), Operation mode burst, Data type random, Continuous mode
channel 60, Channel 60, Monitoring channel 1. The synthesizer will switch
between channel 60 and channel 1.
­ Freq. ch 1 = 1006.2 MHz, ch 124 = 1039.8 MHz.
­ Measure with probe and scope on J904 to see the tuning voltage. It
should switch between 1 and 2 volt. Select channel 124 and it should
switch between 1 and 4.5 volt.
­ J902, 26MHz ref: 26 MHz, >2 VPP
­ Measure at the collector of V904 (UHF TX) and of V906 (LO UHF) to
see that they alternately are on.
­ With a probe connected to the spectrum analyzer, check the RF sig-
nals. The level when they are active should be about 6 dBm.

VHF Synthesizer

Via PCLocals select local mode, RF control, TX mode, Power level 10
(23 dBm), Operation mode burst, Data type random, Continuous mode
channel 60, Channel 60, Monitoring channel 1.
­ Freq. all channels = 232 MHz. The prescaler is placed in V701 and di-
vides the frequency with 2.
­ Check the tuning voltage at J903, 3 ±1.5 V, and check that it moves
when a finger is placed at the oscillator.
­ J902, 26 MHz ref: 26 MHz, >2 VPP
­ Check the supply at V902 or C903, 5 V.
­ Output level at C914/R911 should be ­10 dBm.




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P.A.M.S.
NME­2A
Troubleshooting Instructions Technical Documentation




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