471 = 47 and the number of zeros to follow. This case it's a 1. It means 470 pico farads. The 250 is the voltage rating.
IF EVER you come across a 470 Farad capacitor rated for 250 volts you might have to charge it up once and it will provide power for life. OK, not exactly. But it may take days or even weeks to fully charge. The real question is just how big would a 470 farad cap at 250 be. Answer (unknown to me) would be "As big as a house".
If it was in the part of the board marked "C17" then it is 470 picofarads / 250 Volts
I am the fifth person to say it looks like a 470 pf capacitor so it must true!