Sega Nomad Technical Problems

[RCTM]

I just received a Sega Nomad that I bought off of eBay, and when I plug it in and try to turn it on (with or without a game), all it gives me is a solid-color screen (usually black, sometimes colored) and no sound (unless volume is at max, then there's just a lot of white noise as could be expected).

If I tap or press inward on the brightness wheel, the screen will flash white very briefly and then go right back to black.
I think it might be a power port or voltage regulator issue, but I'm not sure.
The listing showed a photo of it working properly with an official Sega adapter, though that wasn't included. I'm using a third-party ac adapter with adjustable voltage and polarity.
Help please?

[Hobie-wan]

You need to use a real power brick. Most multi power bricks put out 350 mA of power at most and a real Gen model 2 power brick like that uses puts out 850 mA.

[RCTM]

After a bit of searching, I found one, but the plug is just a little bit too wide in diameter. I'll find a plug adapter and reply back with my findings as soon as I can.

[Hobie-wan]

Keep in mind I'm speaking about US consoles.

You found the wrong one then. The model 1 Genesis uses a wider plug with the black plastic in it. You want the later plug with the yellow plastic in it. That's for Model 2 Genesis/Nomad/Game Gear.

[RCTM]

I've just tried it with a MacGyvered battery setup, and nothing changed. So it seems to me that the problem isn't with the power it's receiving, but something inside of it.
Any more ideas?

[Hobie-wan]

Over the weekend I encountered a damaged Nomad that just gives a noise and a gray washed out screen when turned on. At the very least on this one, the can capacitor right next to the power plug is toast. I'm actually surprised it turns on at all. Maybe something similar going on with that one? Have you opened it up to look yet? The 4 corner screws are phillips and the bottom center is the larger 'gamebit' type.

[RCTM]

That sounds exactly the same as the problem I have!
I've now opened it up, though the gamebit screw is missing. I had a sniff around it, and there's a distinctly toasty smell coming from the area around the power plug; it would seem that you're correct. It appears the LED power light has been replaced or resoldered, as there was quite a bit of guff around its points.
There is something that caught my eye almost immediately, though:





Should I be worried about this at all, or am I just grasping at straws?

[Hobie-wan]

The one I was just looking at had a disc capacitor added in and stuck down with the white goop too. So that appears to be a factory tweak.

[RCTM]

Oh, okay. Good to know.
I'll see about getting a replacement capacitor and respond with the results.
You wouldn't happen to know the specifications of the two capacitors near the power plug, would you?

[Hobie-wan]

I do not. That Nomad it back together at the moment and I'm in the middle of something. The big can capacitors have nice easy to read values on them though.