my dendrobium orchids have black spots

Hi,
I am new to orchids, so i have uploaded the pics of my plants, please let me know whether they are healthy. One of the plants have lot of black spots on them, what are they. I have 3 orchids but they are not flowering at all, please let me know if any extra care needs to be taken. I am in Chennai(India), here the climate hot during day and slightly cold during night. I water them every 2 days and weekly once with organic liquid fertilizer.

hi senthil,
they look ok to me, those spots on the leaves could be mechanical, from moving around or animals around the house, nothing to worry about.
i guess only patience is needed to see em blooming.
how long do you have em?

they look fine to me. how much light do they get? i have a secret that keeps my garden
full of flowers.... always buy more, hehehe, that way you'll always have something in
bloom. But seriously, nothing to be alarmed about, just continue what your doing and
maybe give a bit more light short of burning the leaves.

Thanks to all of you for the reply