doesn't work, won't turn on

Hey there,

I just used an multi adaptor to power my Sega Master system 1 Power Base and I think I used the wrong polarity (I assume). Now the Device won't turn on anymore, the power LED doesnt light. I opened it up, but there's no broken part like capacitors or else.

I really don't know what happened, now I'm using the right polarity, and the mainboard gets enough power, no fuses are blown or else...I am really sad about that, so I hope someone of you knows a solution.

Greetings