In full sun? Or have you actually managed to underwater a phal?

had it for about two years, same place dont know what i have done other one is fine, should i give it more water,

Take it our of the cache pot, I assume you have it in one, and look at the roots inside the clear growing pot if they are white then run rain or tap water through them until they start to go green. Don't let your phal stand in water ever. You might want to consider investing in a small tub of orchid feed, it will last for years!