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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Everblue on November 21, 2009, 11:04:31 PM

Title: A4000T PSU - should I replace it?
Post by: Everblue on November 21, 2009, 11:04:31 PM
I was reading some horror stories on the interwebs about the original A4000T PSU getting too hot and damaging motherboards.... Is this an urban legend or real?

I do have access to a few AT PSUs.... will these physically fit in an A4000T case without any modification? Will 200watts be enough?

Thanks!
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 21, 2009, 11:36:59 PM
Given how cheap a replacement AT PSU is, or an ATX with an ATX to AT converter, I would say it is well worth changing that PSU. Look in the gallery under X to see my pics, you will see how I did it to mine.
Title: Re: A4000T PSU - should I replace it?
Post by: Matt_H on November 21, 2009, 11:38:19 PM
I've never heard anything about motherboard damage. As my original PSU started dying, it emitted a funny smell and my system became incredibly unstable. Maybe if I had left it in there I'd have had trouble later on, but who knows.

Replaced it with a standard 200W AT PSU. Direct drop-in, all the screws lined up. Problem solved.
Title: Re: A4000T PSU - should I replace it?
Post by: Amiduffer on November 22, 2009, 03:57:43 AM
I think Karlos installed a special 1/4 size PSU and opened up quite a bit of space in the process.
Title: Re: A4000T PSU - should I replace it?
Post by: amigadave on November 22, 2009, 05:31:48 AM
Quote from: Nostromo;530695
I was reading some horror stories on the interwebs about the original A4000T PSU getting too hot and damaging motherboards.... Is this an urban legend or real?

I do have access to a few AT PSUs.... will these physically fit in an A4000T case without any modification? Will 200watts be enough?

Thanks!

I am also thinking of upgrading my A4000T PSU, but my reason is different.  I have a CyberStorm 604e PPC @233Mhz & 68060 @50Mhz with a ton of Zorro cards completely filling every slot for a Video Toaster/Flyer setup, plus the standard high density floppy drive and an internal ZIP100 optical floppy and an internal Iomega Jaz 1gb drive and finally one or two CD-ROM drives.  With all of that installed inside my A4000T I have been worried about the original PSU not being powerful enough and have thought of replacing it with a good quality 400watt PSU that will fit that also has good cooling characteristics.  So, I am open to suggestions on which brand to choose and which model.
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 07:23:05 AM
Anyone knows where I can buy a good AT PSU brand new online in the EU?
Title: Re: A4000T PSU - should I replace it?
Post by: yogisumo on November 22, 2009, 08:51:36 AM
I checked one of my A4000s with a Kill-A-Watt and it only drew about 75 watts from the ac plug.  I can always check it again to make sure if you want but I think that a decent 200-250 watt power supply should be more than adequate.  I have a csppc 233 in one and a quikpak 060 in the other.
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 10:32:36 AM
The position of the PSU in the A4000T is not really clever at all. It is mounted so that you lose a good amount of space above it. That and the difficulty accessing the innards makes the A4000T case not such a great design functionally. I don't think that installing a smaller PSU will help.

AT PSU: I got mine from a local computer fair a while back, for £6. That vendor isn't there anymore, so online will have to be the next step. But....I would go the ATX route instead. Get rid of the AT, and then open up your options considerably.
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 11:02:29 AM
Will the screws match if I put an ATX case + AT Converter? I dont feel like modding the case.
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 11:19:37 AM
Yes, when I did it there was no need to mod the case.
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 11:20:50 AM
Ohhhh nice. And I can buy any ATX to AT adapter...?
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 11:26:45 AM
Mine was a generic one for a few £ from the computer fair. This is what it looks like in place:

http://www.amiga.org/gallery/index.php?n=2737

If you can, try to get one with a long switch cable. The one I got was a bit short and it has to go through a drive bay to gvet to the front bezel.
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 11:30:00 AM
I checked to ATX PSUs and none of them match the screws. How does the current AT case in my A4T switch on? Is it directly connected to the ON/OFF button on the front of the tower, or through the motherboard? /me is confused.

PS: there are 3 screws on the A4T PSU... 6cm and 14cm afar.
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 11:31:25 AM
Click (http://images.google.co.uk/imgres?imgurl=http://www.antronelectronics.com/images/Cables/ATX%2520to%2520AT%2520Adapter.jpg&imgrefurl=http://www.antronelectronics.com/index.php%3FcPath%3D27&usg=__mPYL5N-lW4jBTum9aUp_CU2BmtU=&h=293&w=250&sz=50&hl=en&start=1&um=1&tbnid=GcqJPDfiA7OlpM:&tbnh=115&tbnw=98&prev=/images%3Fq%3Datx%2Bto%2Bat%26hl%3Den%26safe%3Doff%26sa%3DG%26um%3D1)

Have a look, scroll down.
  (http://images.google.co.uk/imgres?imgurl=http://www.antronelectronics.com/images/Cables/ATX%2520to%2520AT%2520Adapter.jpg&imgrefurl=http://www.antronelectronics.com/index.php%3FcPath%3D27&usg=__mPYL5N-lW4jBTum9aUp_CU2BmtU=&h=293&w=250&sz=50&hl=en&start=1&um=1&tbnid=GcqJPDfiA7OlpM:&tbnh=115&tbnw=98&prev=/images%3Fq%3Datx%2Bto%2Bat%26hl%3Den%26safe%3Doff%26sa%3DG%26um%3D1)
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 11:35:18 AM
Your current AT PSU has a switch from the PSU to the front bezel of the Tower.
You'll need a converter that retains that switch or at least has the leads that you can connect to your existing switch. I replaced the whole lot (a bit more work because the switch panel on the bezel must come off).
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 11:36:58 AM
Here is one where they don't sell the switch:

http://www.power-on.com/images/product/accessories/atxtoat2.jpg
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 11:37:06 AM
Ok, now it makes sense. I still have to find an ATX PSU that fits now.
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 11:44:02 AM
Quote from: X-ray;530740
Here is one where they don't sell the switch:

http://www.power-on.com/images/product/accessories/atxtoat2.jpg


Hmmm, so if I get one of those, I assume I can leave the switch in the ON/OFF button on the front or I have to cut cables/reconnect? I really dont want to do any DIY modjobs.

Basically I want to replace the CPU without modding.

THanks!
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 11:49:40 AM
You won't have to cut: the cable ends clip on to the switch tabs. There is no cutting or modding at all, the only thing you have to be sure of is securing the cables properly.
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 11:58:31 AM
Ah great...  So now, I have two options:

1. Get an AT PSU

2. Find an ATX PSU which fits the holes + Adapter

I would go for option 2 but I have no idea where I can find an ATX PSU that fits as they seem that the screws are completely different, at least on the 2 i got.
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 12:52:51 PM
I'll have a look at mine and see what gives.
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 01:02:21 PM
Thanks please :)
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 01:43:17 PM
OK see here:

http://www.amiga.org/gallery/index.php?n=2737&page=1#comment14648

No problem, all 4 screws aligned.
By the way, ignore the little bracket inside the Amiga case which rests on the upper surface of the PSU.
Title: Re: A4000T PSU - should I replace it?
Post by: Moto on November 22, 2009, 01:59:02 PM
Quote from: X-ray;530728
The position of the PSU in the A4000T is not really clever at all. It is mounted so that you lose a good amount of space above it. That and the difficulty accessing the innards makes the A4000T case not such a great design functionally. I don't think that installing a smaller PSU will help.

AT PSU: I got mine from a local computer fair a while back, for £6. That vendor isn't there anymore, so online will have to be the next step. But....I would go the ATX route instead. Get rid of the AT, and then open up your options considerably.
What would be the advantage of using an ATX PSU over an AT one in the 4000T?
Title: Re: A4000T PSU - should I replace it?
Post by: Everblue on November 22, 2009, 02:48:52 PM
Quote from: X-ray;530752
OK see here:

http://www.amiga.org/gallery/index.php?n=2737&page=1#comment14648

No problem, all 4 screws aligned.
By the way, ignore the little bracket inside the Amiga case which rests on the upper surface of the PSU.


Thanks for the photos :)

Is this one upside down?

http://i55.photobucket.com/albums/g154/Odd_Job/Photo059.jpg
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 04:21:53 PM
Oops it is upside down, yes.
Title: Re: A4000T PSU - should I replace it?
Post by: X-ray on November 22, 2009, 04:24:19 PM
"....What would be the advantage of using an ATX PSU over an AT one in the 4000T..."
--------------------------------------------------------------

For me it is about sticking with newer technology. Might get better cable management, a quieter PSU, that sort of thing.
Title: Re: A4000T PSU - should I replace it?
Post by: rkauer on November 22, 2009, 04:55:15 PM
ATX PSU have all the rails regulated independently.

 AT had only the main rail regulated (5V). Some AT even regulated itself from the 12V rail!!!