ford focus cd player number 1 button fault?

took my 03 ford focus cd player apart to change the leds from green to blue but when it was re-assembled the number one button no longer works it dont seem to be anything ive done wrong ! all i can think of is that its an in built thing that if its disassembled it wont work for security reasons ! this is the second one this has happened to while performing this modification ! (by a friend) its a ford 6000 cd player single disk