Repair question

Hi everyone! I'm a bit stumped and hoping someone can help. I have a Dreamcast (with a GDEmu) that suddenly gave up the ghost, at first it wouldn't output video then it stopped turning on. I did a battery replacement in the controller board, so assuming I messed that up got another one, which didn't seem to work. Then I read from a user here about DreamPSU, so I ordered it. Mine didn't come with a power plug, so I bought a generic multi-voltage plug that seemed to match (12v-2.1a) and still get nothing. I might just assume the plug and/or DreamPSU are bad but I don't want to waste more money, wanted to ask if this thing is even salvageable from your experience? Both GDEmu and DreamPSU are from Ali, but after the GDEmu the console did work for a couple months.