Even the best orchid care you can possible give it sometimes care is not enough no matter what you do Orchids will just start to fade away.
One of my best orchids did this no matter what I did,it was just dying the leaves became very wittered and limp lost all roots, only 2 small roots remained what a sad sight.
This is one of my other orchids last week it lost all its roots but it is also trying to produce a new leaf, to my surprise this one is producing a root at the top of the plant
On the orchid you can see the bright green spot on the base of the plant a new root is growing this orchid is also in water culture. They seem to grow new roots faster in water