There are literally hundreds of thousand of these unit produced.
Through out the history of my ownership of Yamaha keyboards, I experienced only one breakdown.
I have owned the psr2000, psr3000, tyros 3, tyros 4, cvp209, and cvp409.
At the present time, I have 2 units tyros 5, psr-s975, cvp709 and the Genos.
One of my Tyros 5 units just stop working after 3 weeks on the job.
It was an emergency, without it I couldn't work.
I had a steady gig 4 nights a week at the Hideaway lounge in St. Louis.
I called customer service at Yamaha.
They wanted me to take it to a local service center here is St. Louis.
Needlessly to say, I was a little upset.
I was able to work up the ladder and actually got someone that was able to help.
They over night me a new replacement.
They send me a paid Fedex label to return the defective unit.
It was really strange, I used it on the job Friday and at the end of the night I turned it off, put it in the case and took it home.
Came back the next evening, set it up, turned it on and nothing happened.
It didn't even light up.
This is why I purchased the second unit so I wouldn't have to face that problem again.
All and all my experience through the years is that Yamaha equipment is super reliable.
Mark.