I have 3 BIOS files installed in my games/PSX Folder. Before I updated a little while back, all my games worked just fine using a 15Khz CRT. A few games that stopped working after running update_all:
Harmful Park
Kyuiin
Darius Games
Rival Schools
I tried changing formats to bin/cue but still have a black screen for those titles. My region setting is on Adaptive, and some games work fine. Wondering if the latest update has botched some titles, I think it was the last 2 updates with this issue, May 3rd and whichever update came before that.