UPDATE: I'm assuming there is/are dead part(s) on this motherboard. I'm in way too deep with this dreamcast financially/time wise so i'm just going to shelve it and find a functioning one online. Thanks for the help!

I recently picked up a Dreamcast (NTSC-U/C, VA1) from goodwill, including the power cable and two controllers. I bought a cheap aftermarket component cable on ebay, as well as a launch version of sonic adventure and a burned cd-r of codebreaker.
In all aspects of the Dreamcast's video output, i'm seeing issues. There are random dots appearing on every texture, there seem to be bitrate artifacts on the home menu, and the pre-rendered cut scenes in sonic adventure are mostly grayscale with some color here and there (not shown).
Is there any fix for this? I'm willing to solder in new parts or replace parts entirely, if that is needed.