Acoustics Troubleshooting; Introduction To Acoustics Troubleshooting - Nokia RM-645 Service Manual

RM-645
BB Troubleshooting and Manual Tuning Guide

Acoustics troubleshooting

Introduction to acoustics troubleshooting

Acoustics design ensures that the sound is detected correctly with a microphone and properly radiated to
the outside of the device by the speaker. The acoustics of the phone include three basic systems: earpiece,
stereo integrated handsfree (IHF) and digital microphone.
The sound reproduced from the earpiece readiates through a single hole on the front cover (A-cover). The
sound reproduced from the 2 IHF speakers radiates from the sound holes located on the bottom part of the
back cover. The microphone is located on the top side of the PWB, and the sound hole is in the keyboard near
the 0-key.
For a correct functionality of the phone, all sound holes must be always open. When the phone is used, care
must be taken not to close any of those holes with a hand or fingers. The phone should be dry and clean,
and no objects must be located in such a way that they close any of the holes.
Issue 1 COMPANY CONFIDENTIAL Page 3 – 39
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