OP-1 line out, right channel, very very low sound level

Hello! Im new here. Greetings to all!
Couple of days ago right channel from my op-1 stoped working, im getting audio only from left channel.
If i turn down the level on left level i can hear very quite audio in my right ear and the level adjustment works, so i can change from zero to very low level on right channel.

I tried to resolder jack connector on i/o board - nothing… then i unsolder all 5 legs removed the connector and soldered 3 wires directly to board - still the same, i can hear only left channel.

Could it be i/o board issue and replacing it could solve the problem?
Or it could be some internal issue, something like preamp burned (maybe powering on a RME 400, while OP-1 was connected to mic/line inputs and was turned on was not a good idea…)?

Will appreciate any help! Thank you.

maybe your headphones broken? :innocent:

No… iv soldered just wires and then tried to connect them to different headphones.

i guess it’s broken then :frowning:

The question is - whats broken - io board or main board.

So could anyone say the internal amp/preamp of the channels are on the i/o board or on main board?

They are not. The IO board is just a digital multiplex IC, LEDs, mic, power switch and in/out connectors.