Power from PSU to A1200 floppy-connector - safe?
 

Is it really safe - with a Mediator TX - to supply extra power to the floppy connector? Doesn't it cause overvoltage or something? I'd really like to know if someone here does that already. I haven't had the guts yet :)

I don't think this is safe at all, I was advised by Stedy not to plug power there.

But this question is haunting me - even at night I wake up from this nightmare not having a definitive answer. I MUST find the answer! :p
Any dudes/dudettes here with a fried A1200 MB caused by this? :)

Seriously, would this cause danger to the A1200 mobo with/without a Mediator? Any experience with psu power to floppy-connector anyone? Is it really needed in some situations as I have read on the forums?

Hi Bamiga,

I'm not sure what you mean by EXTRA power to the floppy connector.

I often supply power both to floppy drives connected to my A1200s' internal floppy drive headers and (though not at the same time) to ATAPI CD-ROM drives connected to the secondary channels of my IDE spitters EXCLUSIVELY from an AT-PC PSU (i.e., with no connection to the Amigas' PSUs either directly or via the motherboards).

And this has never posed any danger either to the motherboards, PSUs, peripherals or interfaces.

If you are considering supplementing the power available to the floppy drive from the Amiga's PSU due to your Mediator TX expansion options loading the 5V power rail by connecting another PSU in parallel with the Amiga's, then I wouldn't recommend that. (Connecting it in series with the Amiga's PSU would, of course, cause overvoltage.)

Just connect the floppy drive EXCLUSIVELY to a separate PSU and it should be okay.

No, I think he wants to plug a power connector to the A1200s floppy power connector in the motherboard.

That connector is supposed to take power from the PSU at the usual Amiga PSU plug and output it to the floppy. You are not supposed to input anything there. I am pretty sure you will blow shit up.

I used to have an atx power adapter that plugged into the floppy connector on the motherboard. More info here

http://eab.abime.net/showthread.php?p=627088#post627088

Ps. I never had any problems with it, but was just as worried before I plugged it in

I have my floppy drive powered directly from ATX psu already.

Yes this is why I'm being so cautious!

Thanks for trying to clarify :).

As you can all see this question is a shady one, there's no one definitive answer whether it's safe or not. Maybe I should just let it be like The beatles sang :) ...

Hi,

In theory, supplying additional power via the floppy drive connector should not harm the Amiga. You do need to question why you need an additional power feed though.
My best guesstimate for the floppy drive power tracks is 2 Amps of current, allowing for a 10 degree temperature rise (standard safe limit).

The only reason you could need extra power is if your system has a PCI or Zorro bus board but ideally your should connect from the +5V supply direct to this board.

If in doubt, play safe and use another connector from your ATX supply to the high current device.

Ian

Thanks Stedy. This was just a question that needed some answering. The Mediator I think supplies enough juice to motherboard with my ATX psu but the thought of "more power = more stability(?)" was the motivation behind this. But my A1200 has been stable so I'll refrain from using any extra power to the mobo.

rescued this thread.
I am interested. I want to know if my BPPC get 5v stable and have read that this trick increases the voltage.
http://powerup.amigaworld.de/index.php?lang=en&page=38 section 4
http://www.youtube.com/watch?v=XX3HZ...ature=youtu.be

doing that trick you are bypassing the motherboard filter stage because now the power enter from the other side of the mobo making such filters useless
check the pics I attached to see where such filters are located near the power connector
in the left pic 1 filter is used for earlier A1200 versions up to rev 1d3
in the right pic there are 4 filters used in 1d4 and 2b

anyways doing that trick could increase the voltage near the floppy connector zone..making turboboards more stable
so
I don't recommend doing this unless you are having stability problems

Suplying power through floppy power connector does not harm you amiga, but there are risk that one day you forgot it and try accidentally power ON amiga only with floppy power connected. That would blow up you Amiga.

I have Zorro II extender and I used to give extra power to mobo through floppy power connector. If you have mediator just remove original A1200 mobo power connector and solder wires to it and connect them to your PSU, most reliable solution.

Expanded A1200 might be a nightmare, usually supplying power through PCI/Zorro extender to A1200 mobo will cause problems, it just don't work reliable.

I tried it.
I use a Mediator LT4 and ATX power supplie and floppy cable plugged to Amiga and it works!
Really, my ppc did not receive stable 5v.
Do not know if it's a general problem of A1200, or Is that my power supplies do not deliver 5v well.

My Tower Kit (EZ-Z4 from Amigakit came with an adapter that only supplied 12v from a small blue wire to the main power input then rest of the power was taken from the Floppy Power Port so I can confirm it's safe to partialy power your A1200 from this header.

With my A1200 + BPPC/BVision I also added extra power here as it was a recommendation from another user and my system always ran stable and reliably. :)

Well, sometimes I can not understand well the translation my in language.
fitzsteve: then continued with floppy cable connected to the motherboard?
When connect, no crashes or weird things. Amiga also starts at the first.

I fix some and others appear.
Now the graphics of the vodoo 3 corrupt

I'm not sure what you are asking vitux, but as you can see in this Video:

http://www.youtube.com/watch?v=QP5HV8z9lsQ

I put power also to the floppy power header and there are no ill effects. As I said this was recommended to me by another BPPC/BVision user as a way to ensure good clean power getting to the Turbo Board and Graphics card :great

This was my own project I sold recently on Amibay by the way, AFAIK the new user is still enjoying it :D

Edit:

@vitux, if you have issues with your Amiga I suggest replacing the Capacitors, has this been done already?

As for Voodoo, they run very hot, try extra cooling.

fitzsteve: :-)
Ok, understood.
I changed capacitors, but removed and replaced many times (cards wires etc), I have broken one :-)
Now I am using another motherboard witch old capacitors

Anyway now it's just the vodoo, the rest is fine

I know it Vodoo runs very hot, but many years ago, this did not happen and did not use cooling.

fitzsteve: I cleaned the contacts on the Voodoo with an eraser.
has improved somewhat (not sure if that's why).
Now take a few hours to appear corruption and be milder.

Yes, seems to be warming the vodoo, although it is assumed that was designed to not need fan

Glad to hear that helped :)

Although it was sold without a fan they do run extremely hot and whilst the components were tolerant of that heat back in the day don't forget it's now a 15 years old board, to preserve the life I highly recommend extra cooling, a fan over the original heatsink be ideal :great

You can also put mini VGA heatsinks on the Ram chips :)