Delay effect causing horrible loud distortion

[jmegawarne]

Hey all. First time posting here.

I recently bought a second-hand JUNO-Gi. I am not an experienced musician or synth user by any stretch of the imagination, but everything seemed to be working fine. A few weeks later, some of the voices started making a terrible distorted noise at a very high volume. It sounds like a huge cymbal crash when you press a key, and occasionally there is a persistent high-pitched whine directly after.

After some mucking around, a friend of mine discovered that the problem goes away if you go into Effect Edit and turn off the delay in the chorus stage. So that’s some sort of progress.

I thought perhaps it may be an electronics problem, and I am “dangerously amateur” with electronics repair, so I had a look at the schematics. However, I cannot figure out what part of the board would be processing delay — there is no explicitly marked delay circuit or stage. There also doesn’t appear to be any overheating or burnt out components on the board.

I can live with no delay for now, but obviously it’s rather disappointing to have it off all the time.

Has anyone experienced this problem before? Or have any idea what I should be testing/replacing on the board?