Fixing Caller Audio Problems with Nx6 or Nx12 Talk Show Systems
This document applies to all variants of the Nx Series of Talk Show systems and covers issues with loss of caller audio.
Customers will say that caller audio seems to stop on the Nx6 or Nx12 randomly and that rebooting solves the issue. You may be tempted to think of power supply problems; however, we find that it is generally not the case.
There are six filter capacitors on the mainboard of the Nx6/Nx12 that, over time, will age and not provide proper filtering of the power rails.
These capacitors are easily replaceable by someone with the proper soldering skills and soldering tools.
Obtaining the parts
While there are more than 20 of these capacitors used, only 6 require replacement.
The capacitor is a Panasonic, 6.3 Volt, 220uF, SMT style, aluminum electrolytic capacitor, (RoHS compliant) part number EEEHA0J221WP. These are Telos part number 1111-00209 and are available as a parts order from us. You can also purchase these from many on-line electronics parts distributors like Mouser or Digikey.
Replacing the capacitors
Here is a picture of the capacitor. Note there are two small tabs on either side of the capacitor which need to be de-soldered to remove it. One of the solder tabs is shown in this image. Use care when removing not to lift the solder trace from the board.
The capacitors covered by this document are C88 (most important one), C61, C260, C261, C266, C267.
Five of these are located on the bottom side of the board as noted here.
The final capacitor (C88) is located on the top side of the board.
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