Boss BR-900CD mic input issues

[capablecleric]

Basically, when I do vocals with my 900, the sound will cut out every 2 or 3 seconds. It is immensely frustrating, and I really want to know why the heck it's doing this. I have an ST51 hooked up to the back, and it does that no matter what effects are present or lacking, or even if it's selected in microphone or guitar effects. Even with no effects at all it just cuts out.

 

[mjbphotos]

Does it happen with either mic input? Have you tried a different mic and cable? My guess is there is a bad component or solder joint in the input circuit. BR900's are getting a little long in the tooth these days.