Sega nomads no power, inverted pos/neg on the battery pack

[Jmustang1968]

A battery and power supply are basically the same thing,
except that a battery is self contained. The plug is actually just an AC adapter that converts the power from your wall outlet from AC to DC and at the amount of volts and current needed by the device. Electronics love DC.

[theclaw]

Using a .3 A power brick when the official one is .85 is not good. For power bricks,the voltage should match, the polarity should match, and the Amp output of the brick should be the same or higher than what the device needs. The device will only pull as much as it needs.

Well that's the thing, this is an official sega power supply. The one I was using before was for a sega gensis. Red online that the nomad runs on the genesis power supply so that's why I used it.
Back of the nomad says 3.5w at 9V so that is roughly about .38a so technically either of the voltage regulators should do fine.
It would be good to know what actual draw the system has while its running, also im guessing the draw changes based on volume and brightness. But either way it shouldn't be more then .4a

After fixing them I rigged up a battery pack with a 7.4v 2000mah battery and it works just fine also. Mind you im not an electrical person by any means, so I don't quite understand the difference between a power supply and a battery.

Genesis 3 released three years after the Nomad. No way they expected that to work.