Fixing Caller Audio Problems with Nx6 or Nx12 Talk Show Systems

Updated by Bryan Jones


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.

The following procedure requires accessing the inside of the Nx6/Nx12, where the AC line and other voltages are present. FOR YOUR SAFETY, we recommend entirely disconnecting all cables before service. Knowledge of soldering techniques is also required. If you are unfamiliar or uncomfortable performing any of these procedures, please contact us for a RMA to send your unit to us for repair. Full mainboards are no longer available for these units. If you damage the board during these soldering procedures, it can not be replaced. PROCEED AT YOUR OWN RISK.

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.

Please make sure you are installing the new capacitor in the exact same orientation as the old one. These capacitors are polarized and Installing one backwards can have catastrophic results.

Five of these are located on the bottom side of the board as noted here.

For reference, the XLR connectors are noted along the top as J5, J6, etc.

Also note that you can remove the top and bottom dress panels of the Nx to gain access to the whole board without removing it from the chassis.

The final capacitor (C88) is located on the top side of the board.

Let us know how we can help

If you have further questions on this topic or have ideas about how we can improve this document, please contact us.

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