I have a Cisco C90 which used to work flawlessly, It is running on TC4.2.3 firmware.
1. One sudden day the ethernet port start to fail. The ethernet cable is connected from Codec's ethernet port 1 to our wall ethernet port point. It shows "no LAN" and we are unable to communicate with the codec via IP.
2. However, if I connect my laptop directly to the codec's ethernet port, I am able to establish a successful connection.
3. Or if I connect the codec to a normal home router, I am able to communicate with the codec too.
4. I have performed xcom factoryreset.
The wall ethernet port point is 100% working because currently I deployed another C90 loaded with the exact config.db file without any problem.
My guess would be, given that the device works when connected to your laptop, and elsewhere, that the problem was more likely a cable issue in it's original location - either not being plugged in correctly, or a fauty network lead / patch at the other end of wherever the telecommunications outlet on your wall connects back to (or a speed/duplex/port security issue with the switch).
If the unit is now working correclty, I wouldn't think it would be eligible for an RMA...
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Wayne -- Please remember to mark helpful responses and to set your question as answered if appropriate.