Hello,
Just want to share with my keyboard problems I experienced at my local church.
I played my PSR-8000 extensively in my church for about a year when it simply died on me. The display lit up, but didn't respond to anything. Strange, but I sent it out to get it fixed. Soon after in my church a Yamaha P-120 got broken and was sent for repairs again.
While I was questioning the reliability of Yamaha products, I was shocked to find out the power voltage out on my church outlet was in fact 270 volts. Whoa...
Mixers, power amps, effects racks, etc all seem to have survived, but not keyboards and guitar effect 'wall warts'
If you see your wall wart adapters melting out on you, then it might be a sign that the power voltage is too high. It seems like Roland products (an XP-80 and XP-30) can survive the extra volts though.
My current keyboard is a Yamaha Motif... but I am very careful of the power outlets I plug into at various venues now...