Audio Failures - Nokia NSD-6 Disassembly & Troubleshooting Instructions

PAMS Technical Documentation

Audio failures

If audio fails to be heard from the earpiece (or XEAR), check the following:
Check earpiece contacts.
Verify that the CAFÉ EARP and EARN bias is on. If necessary, check the entire receive
path—Rx voice data comes from the RF through the RXIQ bus (CDMA) or LIM_P and
LIM_N (AMPS), then to MAD4 through RXD (11:0) (Refer to schematic). See the Baseband
section of the Service Manual for more detail on RXD bus usage.
The Rx voice data then goes back to CAFE on CAFESIO (0), and then to the earpiece or
XEAR. CAFESIO (2) must also be active.
Conversely, if the transmit audio is not working, the fault could be anywhere in the
transmit path. Check the following:
Check microphone contacts.
Microphone bias.
Tx voice data is transferred from CAFÉ to MAD4 on CAFESIO (1). CAFE-SIO (2) must also
be active. Tx voice data is then sent back to CAFÉ on the TXD bus (See schematic). See
the Baseband section of the Service Manual for more detail on RXD bus usage.
Tx voice data is then sent to RF on the TXIQ bus (CDMA) or AMPSMOD (AMPS).
Issue 1 04/01
Disassembly/Troubleshooting Instructions
Nokia Mobile Phones Ltd.
NSD-6
Page 15