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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
4/00021-2/FEA 209 544/18 D 2(35)
Standard Trouble Shooting Instructions
1 Explanations
1.1 Component placement reference
For component placement see doc.1078-2/FEA 209 544/18
1.2 Pin placement
4/00021-2/FEA 209 544/18 D 3(35)
Standard Trouble Shooting Instructions
4/00021-2/FEA 209 544/18 D 4(35)
Standard Trouble Shooting Instructions
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.
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
4/00021-2/FEA 209 544/18 D 5(35)
Standard Trouble Shooting Instructions
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
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, Z202 GSM1800 and Z205.
Give the board power and start it up.