Nokia 2220 Servicehandbuch

RH-42

Troubleshooting Instructions

CCS Technical Documentation

Page 20

Nokia Corporation Confidential

Issue 2 09/2003

Buzzer does not work

Check spring connectors and C306.

• No sound: Try using a known good buzzer instead. If there is still no sound, change the

UEM (D200)

• Weak sound: Use the Audio test in Phoenix to set the buzzer parameters (frequency,

strength). If it does not affect the sound level, change the buzzer.

Keyboard does not work

Check that there is no dirt between the dome sheet and the PWB. Check EMI/ESD filter
(Z301) that all lines come through. If not, change Z301. If the keyboard still does not
operate normally, try to use the Keyboard test in Phoenix to see if the pressed key is
identified. If it is not identified, change the UPP (D400).

Receiver Troubleshooting

General instructions for RX troubleshooting

Start the Phoenix software and use it to start the required RX mode of the mobile phone.
The troubleshooting flowchart is divided into three steps: (1) general checking, (2) local
checking, and (3) RX chain checking.

Note: Before changing ASICs or filters, all solderings and missing components must be checked visu-
ally. After any possible component changes, the phone must be tuned with the Phoenix autotune SW.

Path of the received signal

Block level description of the receiver:

(Antenna/ext RF) – Diplexer – Duplexer – Low Noise Amplifier (LNA) – RX band filter –
First mixer – 135.54 MHz RX IF filter – IF-amplifier – second mixer – 14 kHz low-pass fil-
ter – adjustable IQ amplifier – Baseband.