Problem playing region 4 dvd's

Question

I have a Yelo 800 dvd, i thought this was a multi region player, I have received 3 dvd's from my brother in Australia all region 4, when trying to play them it is coming up as no disc....I have used the hack code through the remote to gain access to the factory settings and then change it from multi region to region 4....but when attempting to play the dvd it comes up with no disc again! I am at a loss as to how to play these discs through the Yelo!
Many thanks
Simon