Ask general Genesis/MD/Sega CD/32X questions here (for new members)

Hey everyone, I've got a funny issue w/my Genesis.

Recently I got one off of ebay, and it would power on and I could see the "Licensed by Sega" screen, then it would go black, and just sit there. I was reading that it may be an issue w/the contacts, so I went to cleaning my game with some rubbing alcohol (70%) and a cotton swab.

Well, after that, it was still doing the same, so I found some advice (questioning if it's good or bad now) to insert the freshly cleaned game a few times, then clean it off again and repeat, to clean the pins in the Genesis. I tried this and it still seemed to be doing the same.

At this time, I also tried switching the way the AC adapter was plugged into the outlet. I'm not sure if it was this, or the way I tried to clean the system, but I no longer get a power LED on the front of the console.

If anyone here has advice or direction, please let me know, and thanks for reading my problem.

First, if it were me, I'd only use 90% alcohol--it's a bit more expensive, but far less water in it, and water can cause contacts to corrode even moreso.

When faced with dirty console contacts and no decent contact cleaning cart etc, I've used the "clean it with a game with alcohol-wet contacts" method, but I'd strongly recommend that afterward you prop the cart slot door open and blow a fan in it and make sure the contacts are completely dried before powering it on or inserting another cart.

As for the power now not coming on, I sincerely hope it's not that powering it on with wet contacts caused a short inside, and hopefully just an unrelated problem like a bad power adapter or something, but it's hard to say: I have learned the hard way that dropping those power adapters can kill them dead.

Hope this helps, or that someone with more knowledge/experience will drop in and give more info.

I've got a power adapter for an NES and a SNES, but I have read it's a big no no to use those in the Genesis, is that so?

I've heard the same rumor, and I guess the answer is "it depends."

I presume you have a model 1 Genesis (edit: you did state that in the title, my bad, need to learn how to read), otherwise I don't think any Nintendo-made adapter will even fit. If it is model 1, the NES adapter should fit, but not the SNES. We used to use these interchangeably all the time at the game store I worked in, but our warranty was only 90 days....then again, I don't recall a mismatched power adapter ever having caused an issue, but, to be sure....

If the input voltage on the system exactly matches the output voltage of the adapter, AND the input current requirement (rated in mA) of the system is equal to or less than the current output of the adapter, AND the plugs are identical, AND the polarity of the plugs are identical, then you're in business. Rarely does this happen, and supposedly you can fudge a little bit on voltages, but I am no electrician or similar, so be careful, your mileage, etc. :)

That make sense?

Thanks, it does make sense, though I am still wary because I mismatched power supplies on a battery pack a few months back and it nearly exploded right beside me :O

The Genesis is a model one (1601), and the things I read regarding the power adapter issue had to do with some sort of voltage correction (?) the NES had that the Genesis did not.

Would be a major issue if I plugged the Genesis power supply in backwards (upside down) ?

Well, the part about the NES having voltage correction the Genesis doesn't may well be true, so if the voltages are different, be careful, but regardless, when you're talking about what DC power a system needs, if you follow the guidelines I gave (i.e., "everything must match exactly, but output current can be higher than input current"), you shouldn't have anything to worry about.

The power coming out of the wall socket/mains is AC, alternating current, so it doesn't matter how the power adapter is plugged into the wall: even though we have what we call "polarized AC plugs," that's a misnomer--one plug is sometimes larger than the other so that the orientation forces you to plug it in using the position that would allow a ground-plug to be used, if present, but the electricity coming out isn't polarized since it's AC. So no, that wouldn't cause any problem at all.

Okay, if it's alright to plug it into the wall interchangeably, the only thing I can think of that caused the power failure is residual alcohol being left on the contacts that may have still been there when I turned it on. Thanks for clearing up some stuff for me Ghaleon, I hope I can find some way to narrow down the power issue.

I checked the NES connector, it physically fits but the voltage and amperage differed enough to keep me away from trying that. If the Genesis power adapter gets warm (not hot, jut warm) when plugged it, does that mean it's working properly?

Hm, i'd be very hesitant to say "yes," because I've seen these things get damaged and then "work" for awhile, but after several hours they would finally get hot enough to notice (smoke is kinda hard not to notice ;) ). But more to what you're asking: I'd say it's a good sign, but all it means is that it's not completely non-functional, though it may not be putting out the power as it was designed to do if it's damaged. Wish I had more concrete answers for you. I don't know the specs, but I've seen Sega adapters for the same model Genesis that differed in their output, so what exactly does the Nintendo adapter you're contemplating using say that it outputs?

Genesis Power Brick:
Model: 1602-1
Input: 120V AC 60Hz 20W
Output: 10V DC 1.2A

NES Power Brick:
Model: NES-002
Input: 120V AC 60Hz 17W
Output: AC9V 1.3A

Oh, now I can see why there's the Voltage regulator/corrector/magical chip in the NES.. The brick spits out AC current.

Holy crap, you're right. The system itself even says it accepts AC input. This boggles my mind: I have no idea why this would ever have worked, then, when we used to interchange these. Then again, there are 3rd party adapters that have different plugs but the same output on all plugs, and they claim it works on NES and Genesis, like the one below that outputs DC 9V-850mA:

http://video-games.become.com/nes-sn...s--sc736293103

So maybe the NES can accept low-voltage AC but also DC, whereas the Genesis can only accept DC.

If you haven't already figured it out, I'm out of my league here--I assumed all those wall-warts were outputting DC power.

Check out this thread: http://www.sega-16.com/forum/showthr...ier#post151696

Looks like the NES has an internal rectifier, which converts AC to DC, whereas most other systems don't. So you can use a Genesis adapter on a NES, but not the other way around.....maybe that's all we ever did where I worked, anyway.

Well....do you have a NES that you can use the Sega power supply on?

I just tried the Sega adapter in the NES, and I saw the power light flash on quickly, then it went off. So I guess we can call this one the Power Brick?

Out of your league or not, I think we both learned some stuff tonight! ;)

True that! :D

Bit of jolly interesting on this. I performed a test on a SNES using an AC and then a DC power supply. With the AC Supply the SNES drew 600mA-AC (rounded up) with the DC supply it was around 350mA-DC.

Does an Australian SNES expect AC input? My American version is rated for DC input, and the original adapter outputs DC as well.

And if so, does that imply that the internal AC/DC conversion (or rectification, whatever it is) is just over 50% efficient?

Yea the PAL SNES uses an AC adaptor and has an in built rectifier.