since you're using that screen, why don't you try getting the H sync & V sync from the PS2 motherboard to the screen?
I just wanna see if the VGA would still work even if you're not using the LMH1251.
i remember you back then on 2013!
I was watching your 2nd ps2p worklog which you never continued to finish, but I'm still amaze of your 1st work. Welcome back to portabolizing, dude! :D
I think what Ashen did is a VGA but it's only 15 kHz, which means he can't go beyond 31 kHz.
He can only play Normal Display Mode but not Progressive Mode.
your ps2 slim motherboard should be 7900x.
From this picture
trim it that would look like this
and try to make a worklog so you can post your questions there