Vocore Dispaly turns white and black after the second

[Grgur00]

Hi, I followed the steps you wrote on your blog: https://vonger.cn/?p=15349 I can send data to it eg make pixels random colours or black using dd if=/dev/urandom of=/dev/fb1 bs=1000 count=768 comand, but I can't seem to make it a functioning display. If I remove HDMI before booting nothing will be displayed. Please advise