Green light in the top left remains on, but screen never came back.
Then, it looks like that problem is relevant to MCU/display_controller
(I'm not sure whether the devece's display is controlled by MCU or has build in controller) and I'm afraid there will be a need to send devoce tp manufacture to replace it according to their warranty statements. If this will happen I would advocate to move (somehow) your stash to new addresses not related with your SEED on Cold Card Q.