ERICSSON R310 Trouble Shooting Guide

Trouble Shooting Guide, Standard

Applicable for R310s and R310sc

Contents

1 Explanations....................................................................................................................2

2 Network Problems...........................................................................................................4

3 On/Off Problems.............................................................................................................8

4 Audio Problems.............................................................................................................11

5 Display/Illumination Problems....................................................................................14

6 Capacity/Charging Problems.......................................................................................17

7 SIM Problems................................................................................................................18

8 Key Problems.................................................................................................................19

9 Alert Problems...............................................................................................................20

10 Other Problems.............................................................................................................22

11 Revision History............................................................................................................23

4/00021-2/FEA 209 544/31 B Approved according to 1776-2/FEA 209 544

1 Explanations

For component placing see doc.1078-2/FEA 209 544/31.

1.1 Abbreviations

B: Crystal. C: Capacitor. D: Digital circuit. F: Over voltage protection. H: Buzzer, LED, pads for display. J: Connector. L: Coil.

Trouble Shooting Guide, Standard

N: Analogue circuit. R: Resistor. S: Keyboard pads. U: BALUN Component that converts a balanced signal to unbalanced or the other way

around.

V: T ransistor, diode. X: Contact surface on the circuit board. Z: Filter.

DCIO: DC voltage through the system connector for charging. GND: Ground. LED3K: Signal that activates the background illumination. ONSWAn: Voltage from the On/Off key that starts the phone. RTC: Real Time Clock. Clock that keeps track of the time. SIMCLK: Signal from the processor used for communication to SIM, clock signal. SIMDAT: Signal from the processor used for communication to SIM, data signal. SIMRST: Signal from the processor used for communication to SIM, reset signal. SIMVCC: Feed voltage for SIM. VBATT: Battery voltage. VCORE: DC voltage for the processor and memory at, for instance, stand by mode.

Lower than VDIG.

VDIG: DC voltage for the processor and memory. VDSPC: DC voltage for the DSP (Digital Signal Processor). VLCD: DC voltage that controls the contrast for the display. VRAD: DC voltage for the radio part except for the synthesizer.

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Trouble Shooting Guide, Standard

V380B: DC voltage for the radio part. VRTC: DC voltage for the Real Time Clock. VVCO: DC voltage for the synthesizer. I2C: Communications standard for two-way communication using only 2 wires,

clock and data.

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1.2 Pin Placing

Trouble Shooting Guide, Standard

Single diode (PIN diode) Electrolytic capacitor

Five pin circuit (usually

voltage regulator)

Ten pin circuit Crystal N200

Six pin circuit Eight pin circuit

Double diode or single

transistor

N330 and N331 N551 J603

X100

2 Network Problems

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Trouble Shooting Guide, Standard

2.1 Find out if the fault is RX- or TX-related

Connect the phone to a GSM test instrument and try to get SERV at an input signal strength of -68.5dBm.

If the phone does not get SERV at one or both bands, go to section 2.2. If the phone gets SERV, go to section 2.3.

2.2 The phone does not get SERV

Open the phone and check for liquid damage. Make sure that the antenna connector in the frame is not mechanically damaged, dirty or oxidised. Clean or replace it if it is needed. Also check that the antenna connector surface on the board is clean and that it is not oxidised.

Check the soldering of N234, N200, Z200, Z201 and N201. Measure the resistance of R220, R221, R222 and R223 (all 2.7 kohms).

Replace it if it is incorrect. Check that C312 is correctly soldered. If the fault is not found so far, the problem is probably within the LO part or the losses in the

signal path might be too large. It is also possible that the feed voltages are incorrect. Power up the board and start it by pressing the On/Off key.

Measure the VRAD voltage on C501, on the pin close to N700 (3.8V). If the voltage is incorrect, send the unit on according to the local company directives.

Measure the V380B voltage on C500, on the pin close to R427 (3.8V). If the voltage is incorrect, send the unit on according to the local company directives.

Measure the VVCO voltage on pin 5 of N502 (3.8V). If the voltage is correct, go to section 2.2.1.

If the voltage is incorrect, measure the voltage on L500 (VBATT). If the voltage on L500 is correct, measure the voltage on V500, on the pin close to C401 (4.7 V). If the voltage on V500 is correct, measure the voltage on pin 1 of N502 (4.7 V). If the voltage on pin 1 of N502 is correct, measure the voltage on pin 3 of N502 (3.8V). If the voltage on pin 3 of N502 (3.8V) is correct, replace N502.

If the voltage on pin 3 of N502 (3.8V) is incorrect send the unit on according to the local company directives.

If the voltage on pin 1 of N502 is incorrect send the unit on according to the local company directives.

If the voltage at V500 is 3.8V, replace V500, otherwise send the unit on according to the local company directives.

If the voltage at L500 is incorrect, measure the resistance of L500 (0 ohms). If the resistance is correct, send the unit on according to the local company directives.

If the resistance is too high, replace L500.

2.2.1 Check the feed voltages

VRAD voltage for N234:

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Trouble Shooting Guide, Standard

Measure the voltage on pin 5 of N234 (3.8V). If the voltage is incorrect, measure the resistance of L211 (0 ohms). If the resistance is incorrect, replace L211.

If the resistance of L211 is correct, measure the resistance from L211 to ground (>1 Mohms). If it is incorrect, replace C214, C211 and C212.

Measure the voltage on pin 47 of N234 (3.8V). If the voltage is incorrect, measure the resistance of R345 (18 ohms). If the resistance is incorrect, replace R345.

If the resistance of R345 is correct, measure the resistance from pin 47 of N234 to ground (>0.5 Mohm). If the resistance is low, replace C345.

Measure the voltage on pin 62 of N234 (3.8V). If the voltage is incorrect, measure the resistance of L370 (0 ohms). If the resistance is incorrect, replace L370.

If the resistance of L370 is correct, measure the resistance from L370 to ground (>0.5 Mohm). If the resistance is low, replace C373 and R362.

The VVCO voltage for D300:

Measure the voltage on R303 (3.8 V). If the voltage is incorrect, measure the resistance of R303 (18 ohms). If the resistance is incorrect, replace R303.

If the resistance of R303 is correct, measure the resistance from R303 to ground (130 kohms). If the resistance is low, replace C303.

If the fault remains, send the unit on according to the local company directives.

2.3 Connect a call at –68.5dBm input signal and power level 5

If you are able to connect a call, go to section 2.4. If you are not able to connect a call, open the phone and check for liquid damage. Make sure that the antenna connector in the frame is not mechanically damaged, dirty or

oxidised. Clean or replace it if needed. Also check that the antenna connector surface on the board is clean and not oxidised.

Check the soldering on N551, N400 and the components around them. Try to connect a call again. If you still are not able to connect a call, send t he unit on according to the local company

directives.

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Trouble Shooting Guide, Standard

2.4 Read the RX-level while call is connected

Make sure that the output power is 31-35 dBm for GSM power level 5 and that the RX-level value is 43±3 steps.

Lower the input signal to –102dBm and make sure that the RX-level value is 6-12 steps and that the RX-quality value i s 0-2 steps.

If the values are within the limits, but you are not able to connect a call on t he “real” net, make sure that the phone has not been locked out of the system due to theft.

If the RX-level value is too high the phone needs to be calibrated, send the unit on according to the local company directives.

If the RX-level value is less than 38 steps at an input signal of –68.5dBm or less than 5 steps at an input signal of –102dBm then the fault is RX-related.

Open the phone and check for liquid damage. Make sure that the antenna connector in the frame is not mechanically damaged, dirty or

oxidised. Clean the connector or replace it if it is needed. Also check that the antenna connector surface on the board is clean and not oxidised.

Check the soldering on N200, Z200, Z201 and N201. Remove L204 and measure the resistance from pin 2 of Z200 to ground (>100 kohms). The

resistance is usually only a few ohms when Z200 is faulty. If the resistance is incorrect, replace Z200 and mount L204.

If the fault remains the unit may have to be calibrated, send the unit on according to the local company directives.

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