Slipper orchid showing yellow brown at crown
 

Last Friday (8/25) I noticed light yellowish leaves (near crown) on Slipper orchid. I watered that orchid that day. Now today (8/28) after two days, I see that yellow brown mark has spread and become more darker. The photos show the progression. The first two photos from 8/25 and last two photos from 8/28. The only change was I used to water this Orchid once a week and this time I watered it after 4 days since the bark medium was dry. What do I need to do. Appreciate the help.

Photos didn't show. Is it a Paphiopedilum or a Phragmipedium? Neither should dry out at all. Once a week may not be enough watering. If underwatered leaves turn yellow and then brown.

I don't see any photos. But i do suspect under-watering. Slippers (both Paphs and Phrags) need to stay damp. Phrags are often grown sitting in a saucer of water. Paphs not quite as wet, but must never dry out. The watering schedule you describe sounds more like what you'd want for a Phal or a Catt.

Attaching images again. It is Paphiopedilum.

After taking photos when I touched the leaves...those leaves are feeling very loose and feel like they would drop out soon. It seems the whole crown has rotten.

I have this Orchid for almost 7 weeks. All along I have been watering once a week. As you have pointed out with under watering it has been deteriorating slowly and reached this stage.

So how do I save this orchid? Appreciate everyone's help.

At this point just keep it moist. There is a chance it will make another growth from the base. Don't let sun shine on the leaves. It doesn't need that much light.