Procuring Main mother board for Yamaha CVP 503

by Antonio Jose Dias
(Mumbai, India )

Dear Members,
I have Yamaha clavinova CVP 503. 2 years have passed and it is just idle since I cannot repair or replace the main motherboard as it needs repair or total replacement. I cannot get the similar mother board in India Mumbai. And if I do get it is too expensive and then I could buy another used cvp 503 at the same cost of the board.
Can someone please tell me as to how do I order parts from abroad?
Only my main power light comes on and the screen lights up but it is just blue in colour. What I mean is it is a blank blue screen .
Please do help, if someone has a working main mother board or could suggest as to from where I can get one. God bless and thank you.