Pls give a quick solution to help my philodendrons from further dying!!!

[beginnershiner]

We bought in home these lovely philodendrons from our friend's place a couple of weeks ago after pruning the edges as it was too lengthy. It was all good till we changed the soil in the container. Am very badly worried as to what went wrong where and very painful to see these beautiful leaves of a stem branch turning yellow all of a sudden. It's not over watered and also not so deeply rooted. Is it possible to give life to these plants again ? Would be really grateful to get some help in this regard. I have also attached two pictures of these lovely plants.