4.10 SIM Card Interface Trouble. LG KG291, KG290

4. TROUBLE SHOOTING

4.10 SIM Card Interface Trouble

TEST POINT

J202

Figure 19

CIRCUIT

2V85_VSIM

SIM CONNECTOR

SIM_DATA

R235

15K

R236 0

C237

NA

2V85_VSIM

10

9

4

5

6

J202

C5

C6

C1

C2

C7

GND4

C3

GND1

GND3 GND2

1

2

3

7

8

C236

220n

C238

NA

C239

1000p

SIM_RST

SIM_CLK

LGE Internal Use Only - 82 Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

4. TROUBLE SHOOTING

CHECKING FLOW

START

Does the SIM cards supports 3V ?

YES

NO

Change the SIM Card. Our phone supports only 3V SIM card.

Voltage at pin1 of

J202 is 2.85V?

YES

NO Voltage output of VSIM LDO

Is 2.85V?

YES

Replace J202

YES

Resolder J202

Change the SIM Card

And try again.

Does it work

Properly?

YES

Change SIM Card

NO Redownload SW.

Does it work

Properly?

YES

SIM Card will be detected.

NO

Change the main board

Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

- 83 LGE Internal Use Only