If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.
the DC-DC convertor i'm getting has 5v output as well as 3.3v so i decided to take advantage of it and use it to supply 5v to the spots on the PSone screen that have 7805s to increase efficiency. is there anything i don't know about psone screens that would make this not work (i plan on desoldering the 7805s)? if i kept the 7805s and just soldered the 5v from the DC-DC convertor to "out" pin on the 7805s, would the screen get it from the 7805s or the DC-DC convertor?
so i connect the unregulated spots where the 7805s connected to the input on the DC-DC convertor and the output of the DC-DC convertor to the 5v where the 7805s were and the ground that the 7805s conected to to the DC-DC convertor's ground?
do you have a filtered DC-DC supply? If not it could cause noise on the entire bus. The PSOne screen might filter it but i dunno. Test it out, if you get any kind of signal noise with the video or audio, the DC-DC is probabbly the cause. You can make a craptastic filter with some capactiors, but if you are going to remove the 7805's just to add in capactiors, just leave in the 7805's. It will be less work, and less of a chance of something blowing up.
Don't forget about the parts before the 7805, which require more than 5V. I suppose those are for filtering the signal, and they won't work at 5V for some reason.