[App_rpt-users] Trouble with my USB URI

I had a note up and running well with not any real issues, however after about 4-6 months, the system no longer detected carrier on the cor line. Sometimes it would think its always on and sometimes it would think its off. I checked the voltage at the line from the radio and that was working as it should. I even reprogrammed the radio to try it voltage high instead of low for carrier. This did not make any difference. I have tried several radios Radius M100 CM300. All work fine on the IRLP machine and all show proper voltage on the COS signal. I have the DMK URI with the eprom. Can anyone suggest any other diagnostics? I would like to get the Node back up and running and/or order a replacement URI Craig VA3DTF