Sega Nomad dead AC adaptor plug

I recently got a Sega Nomad off of eBay and matched it with a MK-2103 AC adaptor I had in my collection (a Nomad one, actually). The console doesn't power on when I flip the switch and there's no audible "pop" or other sounds of electricity flowing into it, even when I push the DC plug around inside the jack. The "battery" LED does not illuminate at any point, the speakers make no sound, and the display doesn't illuminate or flicker, so I'm assuming that power is not getting from the DC plug to the rest of the machine.

From what I can tell from searching, it is usually a broken cold solder joint on the DC plug. There's a lot of play in the DC jack so I'm assuming that this is the case from a previous owner's abuse (tripping over the power cord). I don't have an appropriate gamebit screwdriver to crack the case open yet, but I'm considering filing down one of my existing ones to fit in the hole.

I'm awaiting a battery pack from a different eBay seller, since from the disassembly pictures I can see that the battery pack and the DC plug arrive at the same destination through different routes. If that works, then I can assume it's the DC plug at fault and can go about reflowing the joint.

Some people mentioned that they had blown diodes on their DC jack - how would this happen, other than applying an inappropriate power supply to the machine?

Any suggestions or advice from someone who's attempted the repair would be appreciated, as I want to make sure I have a good idea about what's going on before I start opening up my Nomad.

Thanks!

 

My experience is that it's not as likely a blown diode so much as a burnt-out 7805 voltage regulator. Although the output of the Genesis/Megadrive AC adapter is 9 volts DC, it's well known that you can use almost any voltage since the regulator will step it down to the right number. When you get the thing open, make sure that you're getting five volts out of the other side of the chip once you verify that the jack is working.

 

smd 7508