Q.phalaenopsis orchid
my orchid had long term beautiful blooms on an ever growing longer stalk. Now all the blooms are gone and the stalk has turned brown and dry. Is it dead? Should I cut the stalk off? How can I promote new growth, ie a new stalk or do I just wait for it to come itself – out of dormancy say?

The brown stalk where the flowers were has died and you can cut it off. Don't worry, that's perfectly normal.
Re-blooming works differently for different orchid species. These articles will help you:
https://www.gardeningknowhow.com/ornamental/flowers/orchids/orchid-care-after-blooms-drop.htm
https://www.gardeningknowhow.com/ornamental/flowers/orchids/make-orchid-bloom.htm
https://www.gardeningknowhow.com/ornamental/flowers/orchids/how-to-prune-an-orchid.htm