Oksana, please do not cut off any more orchid roots without posting a photo of the roots here first. I am afraid you may be mistakenly cutting good roots off of your phals because of a misunderstanding. When looking at the 'root' photo you posted and then looking at the orchid 'without' roots, I see good roots that are missing! I also recommend you go back to the box store and get one more phal and unpot it and take a photo of its roots. Let us see the roots after you have washed them under room temperature water to remove the sphag or other medium. Sorry, I did not see your post earlier. I know here in Arkansas the orchids available locally are very limited, but even the boxstore orchids are not all bad. Make sure the next one you select has firm leaves. Don't worry about a spike or flowers as many times those are not really part of the same orchid (long story...).
Also, on July 26 my orchid society is bringing in a really awesome vendor with whom I have purchased several great orchids. If possible, you should make the trip to Springdale and come to the meeting. You can purchase some healthy orchids and I can help you check the roots out to make sure they are fine. I am the president of the society and, unless something comes up that is out of my control, I will be at the meeting. OSO website.