Chosen Solution
After disassembling ( and re-assembling) my sega dreamcast the AV OUT port doesn’t output any video or sound, the system turns on and the disk drive spins but the vmu also doesn’t seem to indicate the console working, I don’t know if this is a problem with the consoles output or actual bios. Any ideas or ways to check what’s broken / How to fix it?
pop it back open and make sure the solder joints for the AV ports are ok