Atari 7800 pro no power

Hello good morning I bought an atari 7800 pro but when reviewing it I found the following problems First of all, I did not have a power source or eliminator so I chose to bridge the source, according to the information on the Internet it corresponds to 9 volts 1 a, so I set out to connect with alligators and I found that it did not turn on, someone could help me with this regards