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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: lionstorm on January 29, 2003, 01:22:46 PM

Title: reverse power supply
Post by: lionstorm on January 29, 2003, 01:22:46 PM
Hi all,
I bought a A1200 motherboard but unfortunately the power supply was modified so that it uses a hard drive power supply. The original external power supply from the A1200 does not work anymore since from the 5 cables, only 4 remains.
Someone already told me something is missing (the 12V) and that the sound might not be good, which is true : I have a crap output sound.
Can I revert this to use the original PSU ? Else what could I do ?
Lio
Title: Re: reverse power supply
Post by: DaveP on January 29, 2003, 01:34:57 PM
Im not sure Im understanding your problem. Are you saying that
the 12v pin-in from the PSU connector on the reverse of the
mobo is missing? Or that the cable from the PSU to the
PSU connector is missing?

You could run a new cable from the 12v pinout on the PSU
into the mobo ( the hardware specs are in the manuals
that came with the A1200 if I recall clearly ). Or you could
get an A500 powersupply.

The other thing to do is buy a ZIV or a Mediator busboard. If I recall
correctly both of them have power re-routed through them and
power the entire motherboard and themselves. That of course
is best driven by an Elbox or Power tower.

Title: Re: reverse power supply
Post by: blobrana on January 29, 2003, 02:12:43 PM
Weird...
Why would anyone use the HD power supply...
I have a towered 1200 that has a PC power supply , with the usual pc power connector `connected` to the bare wires of the 1200 power lead.

Have you the original lead?
The colours of the leads vary with the differant models...so check with a multi meter.
http://www.hardwarebook.net/connector/power/amiga500power.html (http://www.hardwarebook.net/connector/power/amiga500power.html)

good luck.
Title: Re: reverse power supply
Post by: lionstorm on January 30, 2003, 08:16:38 AM
I have a zorro4 bus board but not in the tower anymore since I dont use my CV643D but a BVPPC instead. I remembered the motherboard was getting its power from the zorro4 board although it often crashes and everything was solved when I discovered I had a kind of an adapter from the winner tower  to plug to the A1200 psu plug.
The problem I have now is different : I bought another motherboard where the little cylinder just behind the psu plug is removed and replaced by 4 soldered wires  which joined themselves in a harddrive like power connector.  I wanted to put this board back to my empty desktop case but it does not work anymore with the original A1200 power supply.
I think the reason to modify this was to plug the board in any pc tower case.
Lio