I just turned on my childhood SNES. It’s been acting up lately but today in the middle of playing super mario all stars the screen just slowly faded to black and then the console basically started rebooting by itself. I took the game out and tried another game. It wouldn’t boot. It turns on but no signal to the TV. I use an HDMI converter. I tried mario kart next and it booted normally. Then I tried mortal kombat and now it doesn’t work at all. I’m also using a universal AC/DC power supply. Could anything I’ve written be an issue?

Last night my DMG was working normally (save for the one vertical line across the screen I didn’t get around to fix). Today I tried turning it on and the GB turns on but there is no sound and no image on the screen. The red LED shines brightly. The same happens if I turn the game boy on even without a cartridge inside. No image and no sound. I opened it up and all the capacitors seem OK and there is no visible corrosion. What could be wrong?