Alejandro,
Did you review the troubleshooting guide?
https://community.cisco.com/t5/mobile-applications-documents/troubleshooting-guide-cisco-proximity/ta-p/3148841
It has a lot of valuable information to troubleshoot problems with Proximity. I...
All other troubleshooting that I know off will need a console cable for the touch panel, only thing else it will be to connect the touch to a codec directly (EX90 or EX60) or other units with even a previous version of TC. If that doesn't work then ...
SX20 version? Do you have another codec that you can connect this unit? Remote or Direct pairing? Do you have the console cable for the touch panel?It's unlikely but we can try to connect the touch panel to another system or a different version of TC...