The Sega Genesis Nomad. What an amazing beast. It didn’t work up until today, and the seller had kindly offered me a full refund if I returned it. Not while I have an empty weekend to do some repairing! I already knew there was a problem with the DC-in jack because it was loose as a goose.

Apart came the Nomad, and the problem became much clearer. The damaged DC-in jack was allowing positive and ground to short together. That also gave me a plausible explanation for why the machine would not run from the external battery pack.

For diagnosis, I traced the power input and temporarily connected one of the DC-DC step-down converters from my Saturn PSU project, adjusted to 9 V. Positive on red, ground on black and… bingo! Life! I had initially wired the DC-DC converter the wrong way around and got absolutely nowhere, although thankfully nothing appeared to have been damaged. In the recording, red runs to TP201 and black to TP202.

On closer inspection I found that the DC-in jack from my Mega Drive 2 was compatible with the Nomad. Both machines use the same tip-positive power arrangement. So I removed the jack from one of my working Mega Drive 2 consoles and fitted it to the Nomad.

I replaced the scratched front screen, cleaned the controller buttons, put everything back together and plonked in the nearest cartridge I could find. It works from the external battery pack as well.

So overall… success! The video above shows the Nomad during the initial tests.

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