No Audio/Video after plugging in third party controller

Recently I started using my Dreamcast again. I found a PS/2 to Dreamcast converter, and tried to use it with a keyboard, but when I plugged it in the Dreamcast seemingly turned off. The light was on, and the fans were running, but there was no video or audio, and the disk tray wasn't spinning. It started working again after I unplugged the power cord out of the back and plugged it back in. I tried the keyboard for awhile, it wouldn't work, and so I unplugged it. When I plugged the controller back in, the DC did the same thing it did before. The method with the power didn't work. It came on when I smacked the side, but then shut off when I stepped away. I smacked it again and it came back on, and I plugged in the DC controller (I had it unplugged while I was trying to get the DC to come on), but it went off after a minute and I haven't been able to get it back on. I have no experience with soldering etc, and I have no idea how to open the Dreamcast.

You've broken it (most probably with the controller converter), buy a new Dreamcast since it will be cheaper than repairing... Oh, and avoid using the converter you used because it could be dodgy.

People without experience should avoid using a solder iron... I tried to modify my SEGA Saturn two years ago and set it on fire, which I ended up buying a new one plus a modified Japanese Saturn. :cool: