Mega CD/Sega CD killing PSUs. Help!

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Hateshinai
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Mega CD/Sega CD killing PSUs. Help!

Post by Hateshinai »

Last week my Mega CD 2 refused to power up. It turned out that the PSU died. It was a PSU I got from a Game Gear (in Europe they have the same plug as the Sega CD and Megadrive/Genesis 1). Everything was fine for a week and now the same thing happened. Another dead PSU (also from a Game Gear). WTF? It was plugged into a surge protector together with other PSUs/consoles which were not damaged. I even unplug the power strip when I'm not using it. Any idea what on Earth is going on? Is the Mega CD defective and if so, how can it kill a PSU? Or am I using the wrong type of PSU?
Apparently the Mega CD2 PSU's output is 1.2A 10V center negative. (I don't have one so I can't check but I think it should be identical to the Megadrive Mk1 PSU).
The Game Gear PSU's output is 0.85A 9V center negative.
Could that 1V difference really put enough strain on the PSU to kill it?
Is it possible to fix a PSU at all?
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Hobie-wan
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Re: Mega CD/Sega CD killing PSUs. Help!

Post by Hobie-wan »

The 1 volt difference isn't as big a deal as the extra .35 Amp the Mega CD wants. Amperage that the power brick provides can be over what the device needs, but if it is under it will strain. A well made brick might just run hot and just shorten it's lifespan a little. A crappy one will burn up pretty quickly and one is lucky if it just kills itself when it goes. Super cheap PC power supplies quite often take at least the motherboard with them when they blow.

Fixing the power bricks is generally not going to be worth the effort even if it is possible. Most are glued shut so they'd be hard to open without destroying them. If any of the windings are toast in the transformer then it's useless. Other than cutting off the wire and plug for another project the power brick is garbage. You'll have to buy another proper one. :(
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Hateshinai
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Re: Mega CD/Sega CD killing PSUs. Help!

Post by Hateshinai »

They were both official Sega PSUs. :cry:
I'll buy some replacements then.

One more question. Using a 1.2A 9v power supply with a console that needs 0.85A 9V should be ok, right?
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ChuChu Flamingo
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Re: Mega CD/Sega CD killing PSUs. Help!

Post by ChuChu Flamingo »

Yeah it will as the voltage regulator will take that just fine.
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Hobie-wan
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Re: Mega CD/Sega CD killing PSUs. Help!

Post by Hobie-wan »

When replacing a power brick, the voltage and polarity should match, but the amperage the brick provides can be more than what the device wants and that is fine. The device will only pull as much as it needs.
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