I just got one S910 out of repair with a problem with the mic signal going in and out. The technician said that he repaired the solder. It was $59.

Right after I got that one back, I had a gig ruined by my other S910 not working. None of the buttons would light up or work. I turned it on and off and reset the OS to no avail. When I brought the keyboard home, it worked fine time after time. Yamaha technical support said that it was probably a component on the main board but not the main board itself.

I was going to bring that S910 in for repair on Monday.

Then Thursday at a gig, I had the same problem with the mic going in and out. I tried a different mic cable, and I had the same problem. This was a small gig, and I accidentally brought in a second speaker. I went straight from the mic into the second speaker, and I didn't have a problem.

I brought the keyboard in and asked them to see if they missed something. They tested it, took it apart. They said it worked perfectly and never failed on them. The technician said that he couldn't think of anything that would be causing the problem.

What am I to do? I'm thinking of getting a third S910 so that I can be sure that one works. I would sell one of the two after it gets out of repair.

Maybe I should get an outboard mixer and reverb unit in case the mic input fails again. I don't know what to do.