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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: doctorq on August 18, 2003, 11:04:01 AM

Title: Almost dead A4000
Post by: doctorq on August 18, 2003, 11:04:01 AM

Hi,

is there anybody out there that's very cool handeling a A4000 PSU?

I have pulled out all pins from the original PSU->Motherboard connector, and just inserted them pin by pin in the connector.

The PSU won't start up when all pins are in the connector, but if I remove the thick yellow cable, the PSU starts up. But that won't boot my migy... :-(

Anyone have the schematics for the A4000 psu? Mayby I connected the pins wrong; I sure hope I haven't blown up the motherboard because they are hard to find...

Title: Re: Almost dead A4000
Post by: duesi on August 18, 2003, 12:08:44 PM

I never heard about a defective A4000 PSU ...
(They are rock solid)
Have you removed the Motherboard from the case ?
If not then do so and check out the Power-connector
on the Motherboard... sometimes they are bad soldered. Look also at the plastic sheet underneath
the Board and make sure there's no shortcut

Title: Re: Almost dead A4000
Post by: tonyw on August 18, 2003, 02:42:53 PM

There were several different models of PSU supplied, and I've never seen a circuit for any of them.

But the PSU is as simple as a crystal set, there's nothing to it. What do you mean "it won't start up"? Do you mean that the fan doesn't spin up when you turn the power on?

tony

Title: Re: Almost dead A4000
Post by: amigamad on August 18, 2003, 02:50:41 PM

This site has info on a4000 socket connectors link here a4000 power conector (http://www.ntrautanen.fi/computers/hardware/misc/a4000_power.htm) :-)

Title: Re: Almost dead A4000
Post by: Framiga on August 18, 2003, 02:57:06 PM

Quote

by tonyw on 2003/8/18 15:42:53

There were several different models of PSU supplied, and I've never seen a circuit for any of them.

But the PSU is as simple as a crystal set, there's nothing to it. What do you mean "it won't start up"? Do you mean that the fan doesn't spin up when you turn the power on?

I agree for modern and cheaper ATX PSU but the A4000 PSU (mine was a Lite-On) was the "state of the art" of PSU.

There is an addictional an quite complex circuit inside (probably protection) that is very well designed. . . .no too simple :-)

Ciao

Title: Re: Almost dead A4000
Post by: doctorq on August 18, 2003, 03:00:04 PM

Yes, the fan won't spin up when I turn the power on.

The motherboard has been removed from the case and I can't see something wrong with the motherboard, or the connector.

Title: Re: Almost dead A4000
Post by: Framiga on August 18, 2003, 03:10:38 PM

Check again the pins position in the PSU>MOBO connector.

Ciao