Diagnostics and troubleshooting phones. Block diagram and principle of operation of a GSM telephone

Lecture



Diagnostics and troubleshooting phones. Block diagram and principle of operation of a GSM telephone

consumer risk priority parameter (RPZ):

RPZ = B x A x E,

where B is the parameter of severity of consequences for the consumer;

A - parameter of the frequency of occurrence of the defect;

E is the probability parameter of not detecting a defect.

Table 1 - Probable defects, their causes and consequences

Type of potential defect

Consequences of a potential defect

Potential causes of defects

Remedy

B, score

A point

E,

score

RPZ, score

Faulty display / sen-keyboard

Does not show
  • Damaged LCD display;
  • microcircuit malfunction;
  • wrong LEDs;
  • software failure;
  • corrosive damage;
  • processor failure.
  • Replacing the display;
  • software replacement;
  • replacement of electronic components;
  • replacement of defective items;
  • controller replacement;
  • contact the service center for diagnostics and repair.

eight

2

one

sixteen

No screen backlight

7

3

2

42

Single color screen

eight

2

one

sixteen

Stripes in the image

eight

2

one

sixteen

Dimmed image

five

four

2

40

Slow reaction to touch

five

6

2

60

It is impossible to enter the menu, dial a number, make a call or answer a call, manage the functions of another phone

eight

one

one

eight

Faulty microphone / speaker

I can not hear the interlocutor / you
  • Faulty cable between microphone / speaker and PCB;
  • damaged case;
  • malfunction chip;
  • processor failure;
  • frequency generator malfunction;
  • receiver and transmitter malfunction;
  • filter failure;
  • software failure.
  • Replacing defective items;
  • replacement of electronic components;
  • microphone / speaker replacement;
  • contact the service center for diagnostics and repair.

eight

four

one

32

You and the other person can hear, but bad

6

four

2

48

Sound Distortion / Noise

6

five

2

60

Missing / missing sound

7

four

one

28

Defective charge

Not charging
  • Burnout of PP conductors
  • battery failure (sharp drop in capacity);
  • charger defective;
  • sharp voltage drop;
  • damaged charging connector;
  • software failure;
  • poor contact between the battery and the phone;
  • failure of the power amplifier;
  • defective voltage regulator;
  • broken ceramic plate quartz resonator;
  • virus type "Carib" (always turns on Bluetooth).
  • Replacing faulty electronic components;
  • replacement of components;
  • replacement of the charging connector;
  • replacement; battery;
  • exclusion of voltage drops;
  • stabilization of output parameters;
  • remove the virus;
  • contact the service center for diagnostics and repair.

eight

eight

2

128

Fast discharge

eight

eight

2

128

Phone disconnect

7

6

3

126

Does not show battery indicator

five

2

one

ten

No network / phone does not see the sim card

Barring outgoing calls / messages
  • The sim card is not working;
  • SIM card expired

- the contacts of the sim-receiver are broken;

  • software failure
  • damaged antenna;
  • Failure of the operational amplifier;
  • failure of other electronic components.
  • Install another sim card;
  • antenna replacement;
  • replacement of defective items;
  • replacement of electronic components;
  • contact the service center for diagnostics and repair.

eight

2

2

32

Barring incoming calls / messages

eight

2

2

32

Cellular signal icon is not displayed.

five

four

one

20

The appearance of the inscription "emergency call"

7

four

one

28

No interaction with computer

Cannot use the phone as a modem
  • Software failure;
  • damaged USB wires;
  • damaged USB connector.
  • Software replacement;
  • replacement of components;
  • Replacing the USB-connector;
  • contact the service center for diagnostics and repair.

four

6

3

72

Unable to exchange data

five

five

3

75

Internal memory malfunction

Cannot save files
  • Software failure;
  • processor failure;
  • microcircuit malfunction;
  • virus.
  • Software replacement;
  • CPU replacement;
  • replacement of electronic components;
  • remove the virus;
  • contact the service center for diagnostics and repair.

five

four

3

60

The vibration does not work

No vibrating alert
  • Failure of the vibration motor;
  • defective loop between the vibration motor and the PP;
  • chip malfunction.
  • Replacing the vibration motor;
  • replacement loop;
  • contact the service center for diagnostics and repair.

five

6

one

thirty

No image when taking photos / videos

There is no possibility to photograph / record video

- Damage to the lenses;

- malfunction of the chip.

- the penetration of the electrolyte capacitor to PP.
  • Lens replacement;
  • contact the service center for diagnostics and repair.

five

3

2

thirty

Blueooth does not work

Cannot find another device / cannot find your device;
  • Software failure;
  • microcircuit malfunction;
  • virus type "Carib".
  • Software replacement;
  • replacement of electronic components;
  • remove the virus;
  • contact the service center for diagnostics and repair.

five

6

2

60

Cannot transfer / receive files

five

five

3

75

Does not turn on / off

five

3

2

thirty

Mobile restarts / freezes

Not user friendly
  • Software failure;
  • failure of the power amplifier (consumes too much current);
  • The battery is not working properly.
  • Software replacement;
  • replacement of electronic components;
  • battery replacement.

6

five

3

90

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Diagnostics, maintenance and repair of electronic and radio equipment

Terms: Diagnostics, maintenance and repair of electronic and radio equipment