I have a ten year old clavinova cvp87a- its does not turn on immediately but sometimes comes on after a few minutes then turns off sometimes immediately sometimes after playing for 10 minutes.When on machine is fine and does all functions. I love this clavinova its superb.

Anu suggestions please -does this machine have a replaceable battery inside ? would this affect on/off function if run down

most likely does have a battery, but I'd check the power supply as well. If it stayed on, gets hot and fails, as you explain. that could be anything, but since it's a clavinova it won't be a big issue to fix.