ts 480 not transmitting

[9a4na]

Hello to the group.
I have ts 480 that has been working remotely for almost two years without problem.
Since few weeks it does not transmit. It connects as it should, receiver is working ok.
When i press key in cw mode I hear side tone but led stays green radio does not transmitt.
In SSB mode when i press ptt on mike led goes to red to tx but when talking into the microphone nothing. Modulation is not going thru.
Any idea how to solve this problem?
Thank you in advance.
73 Zeljko 9a4na

[OH6FSG]

I have had same issue 2 weeks ago.  The reason was simple but not very obvious. In the Radio end, one setting was changed. Codec out gain was 0, should be 255. This has happened once before after few weeks shutdown.