I ended up getting the 3 fans to show by plugging the 3rd fan in between the other two plugs. so plugs 1,2 & 3.

It is hashing now... but I am a bit sceptical because it doesn't explain how they just drop out randomly...

Fingers crossed... I have sent back a total of 7 hashing boards now... Not keen on another 3..

Cheers, I will keep you posted