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SpooNMan · Joined: 31 Oct 2007 Posts: 89

I just received a second NOS Magic Drive external floppy and the disk drive is dead (Light just stays on and it says NO DISK). This is the second brand new (old stock) boxed unit where the floppy drive appears to be DOA. Is this a common problem with these drives or something?

madman · Joined: 07 Jul 2006 Posts: 598

I assume you're powering the drive correctly?

SpooNMan · Joined: 31 Oct 2007 Posts: 89

madman · Joined: 07 Jul 2006 Posts: 598

This is the person on EBay? Even for a supposedly NOS drive, that's a lot of money. If you bought a couple, are you interested in selling a box from one of them?

SpooNMan · Joined: 31 Oct 2007 Posts: 89

CrackLtd · Joined: 05 Feb 2007 Posts: 239

a) stop using mega drive psu's for copiers and/or floppies, they are to strong.

b) a magic drive is an generic stock 1.44MB floppy drive, value < $5, the little pcb in the back of the drive just holds an regulator and a relais.

SpooNMan · Joined: 31 Oct 2007 Posts: 89

MottZilla · Joined: 08 Sep 2004 Posts: 765

Too powerful? I could see your point if the voltage was higher than needed for the regulator which takes it down to 5v anyway. But excess amperage? Unless the device draws it, it makes no difference.

CrackLtd · Joined: 05 Feb 2007 Posts: 239

I am no tech, but even i know that a high ampare value rises the actual voltage output. Lets say you have an 9V/1,2 Amps PSU and the unit you use it with only draws 400mA the resulting Voltage is around 12Volt wich of course is way to high. The given Volatage value is only true if the drawn ampare matches the value the PSU is giving. Otherwise the Voltage is varying. So, 9V/1,2Amps is to strong for any of the copiers and is to strong for the magic drives. The Sega Mega Drive PSU has 10V(!) by an Ampare Value of 1,0. Which is to strong. Easy as this. The regulator tries to compansate to much power with produced heat, there is point where the regulator cant stand that anymore. In most cases of broken copiers and magic drives just this regulator is broken. Wrong polarity will destroy this regulator most times instantly. -- There is Wallplug PSUs that have fixed Ampare Output but with selectable Voltage and polarity selector. Also most times they come with exchangable plugs. Choose one with 800mA, these are perfect to use. If you have one with a fixed Ampare value of 1 or 1,2 select 7,5V instead of 9V. On units that draw around 800mAh that will result again in around an effective output of 9V.

MottZilla · Joined: 08 Sep 2004 Posts: 765

Is this something that only applies to Direct Current? Because otherwise that would totally mess up AC power in your house. Outlets in the US are around 110v to 120v. But the amperage you get depends on your electrical service, not everyone has say a 200 amp service. Really I've never heard anything like what you are saying before. I do agree that with voltage you don't want too much as the regulator will just have to bring it down to 5v. I've always used my Sega MD Model 1 PSU for my Game Doctors and Double Pro Fighter. Haven't had any problems.

madman · Joined: 07 Jul 2006 Posts: 598

ericj · Joined: 09 Nov 2009 Posts: 32 Location: Oregon, USA

If that were true, we could simply use 1V power supplies with varying ampere/current ratings. Of course, this makes no sense; you'd just get varying charge flow rates of 1V.

I would guess that most voltage regulators are blown due to someone using an AC Adapter with incorrect polarity since copier power supply circuits don't have bridge rectifiers.