Bulbophyllum medusae just arrived, have some problems?

[Asparago1885]

Hi everyone, sorry for my english, I try my best. This is my first post.. and I’m already asking some help from the experts. I’m relatively new with bulbophyllum and I’m “studying”, but I still have not the “eye” to understand the difference within some imperfections or some problem. Two days ago I received as a gift a Bulbophyllum medusae. Unluckily they told me that there was some delay and this small bulbo has been keep in the darkness for a week or maybe more. When I had received the bulbo I checked the roots and the soil. I think that the result was good, no any visible rot and the substrate was maybe a little bit old but well made and not too wet. I kept this substrate to not traumatize the bulbo in the first period. But.. there are some well-defined black spot and others black areas, especially in the smallest bulb. Also some bulb is tending to yellow. All the areas aren’t soft (like a cactus rot to make an example). I’m keeping the bulbo at 21º-24º C and helping the humidity level with a saucer full of expanded clay and a very light daily vaporization for now. Also good bright light (just from the third day, to acclimate the plant). How I have to act? There are any chances of survival?
Thanks a lot.
P.S. I can make again the photos if aren’t enough to understand.