What is the new psu (your 5700 needed 600, the 7700 needs 750W), are you connecting 2 seperate pcie cables from psu to graphics card (not 1 into 2 split).
Did you use DDU to remove all traces of the old 5700 driver and freash install the new card driver.
My PC- Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, NM790 2TB, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T.