My S910, I've had it for almost 11 years now.
Of course, I always try to keep the instrument up to date by fixing minor issues when necessary (changing rubbers, buttons, etc.). In all these years I've had it, I've only needed to replace the circuit board once. Everything is working perfectly on it.
I think having a good and trustworthy technician also contributes to the longevity of the instrument.
Thank God I'm an old customer of one nearby who specializes in this, including repairing sound equipment, and he has always fixed my keyboards, since the time I had the PSR510 when I didn't even have a cover to protect the keyboard, I was still very young, and the sustain pedal was still a novelty.
Regards,
Gabriel