Tait TP9100 - Page 146

146 Interface Fault Finding TP9100 Service Manual
© Tait Electronics Limited May 2005
Task 8 —
Internal Speaker/
Microphone Faulty
Use this procedure for the following faults:
■ no internal speaker audio
■ internal speaker audio distorted
■ no transmit modulation from internal speaker
■ modulation distorted from internal speaker
These symptoms can indicate a fault with the speaker, the speaker pins, or
the CODEC & audio circuitry.
If the speaker/microphone is faulty:
1. Remove the front panel of the radio, and replace with a front panel
that has a known good speaker.
2. Reassemble and power-up the radio. Check the functionality of the
speaker/microphone.
3. If the speaker/microphone operates as expected, the speaker was
faulty. Discard and replace with a new one (see “Spare Parts” on
page 289). If the speaker/microphone is still faulty, proceed to Step 4.
4. Check the integrity and soldering of speaker pins
SPKR_POS and
SPKR_NEG. See Figure 7.2. Re-solder or replace as required.
5. Recheck the functionality of the speaker/microphone. If still faulty,
reconnect the original speaker and go to “CODEC and Audio
ault Finding” on page 269.
Figure 7.4 PCB layout showing R924 and R925 (top side)
R924 indicating
non-3V3
end (*)
*
R925 indicating
non-3V3
end (*)
*