The Sega Genesis Nomad. What an amazing beast.

It didn’t work up until today. 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!

That was a diagnostic experiment rather than a general power-supply recommendation. Sega’s own manual specifies compatible Genesis 2 and Game Gear power adaptors for normal use.

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.

A great success!

The video below shows the Nomad during the initial tests.

Sources