Ericsson R250 Service Manual
Standard Trouble Shooting Instructions
Standard Trouble Shooting Instructions
Applicable for R250s PRO
4/00021-2/FEA 209 544/18 D Approved according to 1776-2/FEA 209 544
Standard Trouble Shooting Instructions
Contents
1 Explanations........................................................................................................................3
2 Network problems...............................................................................................................6
3 On/Off problems .................................................................................................................9
4 Audio problems.................................................................................................................13
5 Display/ Illumination problems.......................................................................................18
6 Capacity/ Charging problems..........................................................................................22
7 Sim Problems.....................................................................................................................24
8 Key problems.....................................................................................................................27
9 Alert problems...................................................................................................................32
10 Data communication problems........................................................................................33
11 Other problems.................................................................................................................34
12 Revision History................................................................................................................35
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1 Explanations
1.1 Component placement reference
For component placement see doc.1078-2/FEA 209 544/18
1.2 Pin placement
Standard Trouble Shooting Instructions
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Standard Trouble Shooting Instructions
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1.3 Abbreviations
B: Crystal.
C: Capacitor.
D: Digital circuit.
F: Over voltage protection.
H: Buzzer, LED, pads for display.
J: Connector.
L: Coil.
N: Analogue circuit, power amplifier at some phones.
R: Resistor.
S: Keyboard pads.
Standard Trouble Shooting Instructions
V: Transistor, diode.
X: Contact surface at the circuit board.
Z: Filter.
DCIO: DC voltage through the system connector for charging.
GND: Ground.
LED: Light emitting diode e.g. the background illumination.
LO: Local oscillator.
RTC: Real Time Clock, the clock that keeps track of time.
SIMCONCLK: Signal from the processor used for communication to SIM, clock signal.
SIMCONDAT: Signal from the processor used for communication to SIM, data signal.
SIMCONRST: Signal from the processor used for communication to SIM, reset signal.
SIMVCC: Feed voltage for SIM.
VBATT: Battery voltage.
VDIG: DC voltage for the processor and memory.
VDSP: DC voltage for the DSP (Digital Signal Processor).
VLCD: DC voltage for the display that controls the contrast.
VRAD: DC voltage for the radio part except the synthesizer.
VVCO: DC voltage for the synthesizer.
I2C: Two line serial communications standard using one clock and one data
line.
PWM: Pulse Width Modulation
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2 Network problems
2.1 Find out if the fault is RX or TX related
Connect the phone, with the signalling program, to a GSM test instrument and try to get serv at 68,5 dbm signal strength.
If the phone gets serv, go to the section 2.1.2.
If the phone does not get serv, the fault probably is dependent on the LO part,
or the losses in the signal path are too great, go to section 2.1.1.
2.1.1 The phone does not get SERV
Standard Trouble Shooting Instructions
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Check visually the antenna connector X101, checks if it is damaged, bad soldered or dirty.
If necessary, replace X101.
Check for bad soldering at C314, C318, C319, N301, N302 and N303.
Measure the resistance and replace the faulty component of C530, C531, C532, C533, C534 and
C535, all >200 kohms.
Measure the resistance and replace the faulty component of
C850>100 kohms, C851>1kohm, C833>1kohm, C853>100kohms.
Check for bad soldering at Z250, Z500, Z201 GSM900
Give the board power and start it up.
• Measure VRAD (3,8V) at C433.
If the voltage is incorrect, go to the section On/ Off problems.
• Measure the DC voltage at N303 pin4 and pin6.
Pin 4 = variable control voltage between 0,8-2,8V (usually 1,7V at the start).
Pin 6 = variable feed voltage (3,3V usually at the start of the board).
If N303 pin 6, the feed voltage is too low or missing.
, Z202 GSM1800 and Z205.
Check the soldering at D105, D103 and D600 pin8 and pin102.
Measure VVCO 3,8VDC at N410 pin5.
If not, replace N410.
If yes 3,8V at N410 pin 5, measure the level 3,8V at V305 pin 2.
If yes 3,8V at pin 2, replace V305 and C321.
If no 3,8V at pin 2, replace R301.
If N303 pin4, the control voltage is too high (3,6V).
Replace N301.
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If pin4, the control voltage is too low or missing.
Measure the resistance of R312~22 kohms.
If R312 is ok, measure the control- voltage 1,7V at N301 pin5, at the start of
the board.
If the control voltage is too low or missing, replace N301 and C317.
If the control voltage is ok at N301pin5 and too low at N303 pin4,
replace C319 and C314.
If the fault still remains, send the unit on according to the local company directives.
2.1.2 The phone gets serv
Set the GSM test instrument at power level 5 and the signal strength -68,5dBm,
for GSM900
.
Standard Trouble Shooting Instructions
To try GSM1800
Set up a call to a GSM test instrument.
If it works.
Go to the section 2.1.3,read the RX level from the GSM instrument while the call is connected.
If it does not work.
Probably the fault is located at the TX.
If calls cannot be connected at the l ower channels only, then the fault is N570,
and the phone can not be repaired at this level, send the unit on according to the local company
directives.
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Check visually the antenna connector X101, if it is damaged, bad soldered or dirty.
If necessary, replace X101.
Measure the resistance from the P401 test point, to ground >10 kohms.
If the resistance is too low, usually 200 ohms, then N401 is damaged, and the phone can not be
repaired at this level, send the unit on according to the local company directives.
Check that L403 not is burned.
, set the power level 0 and the signal strength of -68,5dBm
Check the soldering at Z205, Z203, GSM900
Check the soldering at N560 and N570.
Measure the resistance at C853 >100 kohms, L560 and L223~0 ohm.
If the fault still remains send the unit on according to the local company directives.
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and Z204 GSM1800.
Standard Trouble Shooting Instructions
2.1.3 Read the RX level value from the GSM instrument while the call
is connected
If the RX-level is at 40-46 steps, make sure the output power is 31-35 dBm for GSM 900(power
level 5) or 28-32dBm for GSM1800
(power level 0).
If it is correct, lower the signal strength to -102dBm for GSM 900
is 6-12 steps and that the RX-quality value is at 0-2steps.
For GSM 1800
RX-quality value 0-2 steps
Make a call to the public net and check the audio part.
If it is ok, the phone has passed the test.
If the phone can not connect a call to the public net:
If it not is locked out, replace D600.
• If the phone can’t connect a call at any of the lower channels (GSM900)
channels, or if it can not switch from another high channel to channel 1 (or several lower
channels) it means that N570 is faulty and the phone can not be repaired at this level, send
the unit on according to the local company directives.
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Make sure the antenna connector X101 is not damaged, badly soldered or dirty.
If the RX-level value is below 40 steps at -68.5dBm signal strength there is an RX -related fault.
Measure the resistance of C530-C535 >200 kohms.
the signal strength should be -100,5dBm,the RX-level value 7-13 steps and the
Check if the phone is locked out of the system due to theft.
and make sure the RX-level
but at other higher
Check the soldering at Z250, Z500, Z201 GSM900
If the fault remains send the unit on according to the local company directives.
If the RX level value is above 45 steps at input signal -68,5 dBm or the RX quality is high, the
phone needs to be calibrated. Send the unit on according to the local company directives.
If the output power is too low, check the soldering at N560, N570, Z205, Z203 and Z204.
If the fault remains, send the unit on according to the local company directives.
, Z202 GSM1800 and Z205.
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3 On/Off problems
3.1 Starting the phone pressing the On/Off key
1. Remove the battery and make a visual check of the battery connectors,
make sure they are intact.
2. Insert a dummy battery into the phone, start it up by pressing the On/Off key and check the
current consumption.
3. If the phone starts, check the charging function by connecting a charger at the system
connector. If it does not charge go to chapter Charging problems.
4. If the phone does not consume any current when the On/Off key is pressed, go to 3.2.
5. If the phone consumes 1-200 mA, starts (and request for SIM, seeks net, etc....) and works
as long as you keep the On/Off key pressed, go to 3.3.
Standard Trouble Shooting Instructions
6. If the phone starts but consumes more than 200mA go to 3.4.
7. If the phone does not start try to reprogram it in t he flash programmer.
8. If the phone does not start in the flash programmer go to 3.5.
9. If the phone is programmable but not start afterwards go to 3.6.
3.2 The phone does not consume any current when the
On/Off key is pressed
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Make sure the battery screws are correctly tightened.
Make sure the system connector pads-J602, not are damaged or burned.
Remove the domefoil, according to mechanical Instructions, and make sure that the keypads are
not broken, liquid damaged or dirty especially the On/Off key.
No further action should be taken for a liquid damaged telephone.
Give the board power.
• Make sure there is VBATT voltage at the pad of the On/Off keypads.
If VBATT is missing there is a foil damage, send the unit on according t o the local
company directives.
If VBATT is correct, measure the resistance from the other pad, ONSRQ, to V702 pin
1~0ohms.
If the resistance is incorrect there is a foil damage, send the unit on according
to the local company directives.
If the resistance is correct, replace V702.
If the fault remains, send the unit on according to the local company directives.
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Standard Trouble Shooting Instructions
3.3 The phone runs as long as the On/Off key is pressed
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Make sure the system connector pads-J602 not are damaged or burned.
Mount the board in the fixture. Start it up and keep it running by keeping DCIO high.
• Measure the voltage at C692 >3V.
If it is correct, check the soldering at D600 pin 119, measure the resistance of C692
>200 kohms
If the resistance is incorrect replace the capacitor.
If the resistance is correct, measure the input voltage at N706 pin 2 (VBATT),
and the output voltage at pin 3 ~3.5V. Make sure that there is ground at N706
pin 1.
If VBATT or ground is missing there is a foil damage, send the unit on
according to the local company directives.
If VBATT and ground are correct but not the output voltage, replace
N706.
If they are all correct, measure the voltage at the positive side of the
backup capacitor, C720 ~3.2V.
If it is incorrect, measure the resistance of R720 ~180 kohms,
and R719 ~47kohms.
If they are correct, replace V711.
If the voltage is correct, measure the resistance from the
positive side of C720 to C692 ~0 ohms.
If it is incorrect then there is a foil damage, send the unit on
according to the local company directives.
3.4 The phone consumes more than 200 mA
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Make sure the system connector pads not are damaged or burned.
Mount the board in the fixture. Start it up and keep it running by keeping DCIO high.
• Check the current consumption again.
If it is more than 200mA, replace the display and the elastomer and try again.
• Check the resistance from VBATT to ground >1 Mohms.
If it is less, send the unit on according to the local company directives
• Check VDIG on N702 pin5 and VDSP-N701 pin5 voltage ~3.2V.
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Standard Trouble Shooting Instructions
If any of the voltage are too low, measure the resistance from it to ground (VDIG >500 ohms, VDSP - >25 kohms).
If the resistance is correct, replace the corresponding regulator.
If it is too low, send the unit on according to t he local company directives.
If any of the voltages are too high, replace the corresponding regulator.
• Measure VRAD on N412 pin5, VVCO-N410 pin5 and VRPAD-N411 pin5 volt-ages ~3.8V.
If any of the voltage are incorrect, measure the resistance from it to ground (>50
kohms).
If the resistance is correct, replace the corresponding regulator.
If that does not help, or the resistance still is too low, send the unit on
according to the local company directives.
3.5 The phone does not start in the flash programmer
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Make sure the system connector pads are not damaged or burned.
• Measure the resistance of R421 ~ 0.1 ohm.
If R421 is replaced, the charging function has to be verified. If it’s incorrect, send the
unit on according to the local company directives.
Mount the board in the fixture. Start it up and keep it running by keeping DCIO high.
• Check VDIG-N702 and VDSP-N701 voltage 3.2V.
If any of the voltage are too low, measure the resistance from it to ground (VDIG >500
ohms, VDSP >25 kohms).
If the resistance is correct, replace the corresponding circuit, VDIG - N702,
VDSP - N701.
If the resistance is too low, send the unit on according to the local company
directives.
If any of the voltages are too high, replace the corresponding circuit.
• Check the power reset (PWRRST) voltage at C710 >3V
If it is lower, check R704 ~0 ohms and R725 ~100 kohms.
If they are ok, first replace C710 and if it does not help, replace N703.
• Measure the voltage VRAD-N412 pin5, VVCO -N410 pin5 and VRPAD-N411 pin5 voltage
~3.8V, fig.
If any of the voltages are incorrect, measure the resistance from it to ground >50
kohms.
If it is correct, replace the corresponding circuit.
If the resistance is too low, send the unit on according to the local company
directives.
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