No audio signal in Colibri T20

Hi,
We are using Colibri T20 with Iris V1.1 carrier board for call box application, Iris audio output signal connected to external mono 4W amplifier module and its working fine earlier.
while testing today no audio output but other functionalities everything is working fine, then we replaced new T20 and its working fine.

Please suggest how to rectify this issue and recover T20 module Audio portion
Thanks in advance
Panner

Dear @panneerrajan,
Please first of all try to recover the module by setting it back to default settings. You can do this through the recovery mode:
http://developer.toradex.com/knowledge-base/txx-recovery-mode
Let us know if that helped.