Reply to Help my s4's effect section is not working properly

So last evening I had an last minute call to come and play at a guy's party and I ended up changing 2 things (I know terrible idea) I put my s4 into 4 decks internal mixer mode and I went to 4 effect units rather than the two I was using before, now when I push the effect select buttons underneath the gain I can only select effect bank 1 with deck a and effect bank 2 with deck b... button 2 for deck a and button 1 for deck b just seem to not do anything...I am pretty confused, I looked through the manual but couldn't find any sort of information about selecting effects in 4 effect bank mode, could someone please help me out..