Shruthi XT Strange Behaviour

Hi there.
I’ve been using Shruthi’s for a very long time and recently my XT started to behave … I wasn’t using it for quite some time and after connecting it recently the strange behavior started happening. When receiving midi notes from the octatrack two things happen, first one some of the notes seem to be stuck on, some of them seem to be cut off before the end. Seems like it’s choking on the midi provided by the octatrack but I’m not sending anything that was a problem before. Another issue is when I play given sequence after some short time the preset is being changed to something else. I thing also some of the button are not behaving properly, especially ones for oscillator shape. I assume this might be issue with one of the ICs, but I’m not quite sure from which I should start investigating. The only thing I recall might cause the problem, was that XT slid from the stand I use and bumped on the desk but it wasn’t more than 5cm to be honest and this unit survived many rough club gigs :stuck_out_tongue:
I’d be more than grateful for any tips on how to pinpoint what might be wrong and how to “debug” the issue. Thx!

Looks like the incoming MIDI data is being garbled. You can try replacing the 6N137 optocoupler, checking if it is correctly pushed in its socket, but also checking the soldering of all the components involved in the MIDI reception circuit.

Hi there. Thx for the quick reply. Yup the 6N137 seems to be broken, put the one from another shruthi I have and everything is working fine! Thank you!