Modifying an AT case to use an ATX power supply **Got it working!!**

[wyvrn]

I am replacing an AMD 200 system for a friend, and trying to keep costs low. Her case is perfectly fine and we want to use it for a Duron 1.2 Ghz and ECS K7S5A, I purchased an ATX AMD approved PS as well. From this AT power supply, there is a cable with thick outer covering going to power switch, it has four conductors. The colors are white, black, blue, and brown. I know black is ground, but what are the other three? The ECS board has two a two pin connector for power, being normal ATX. So I guess I will not use two of the conductors on the AT power switch? Could someone please tell me or point me to a site that explains AT power supplies, all of the AT power supplies I have used didn't have this separate cable (at least I think they didn't). Thanks!

Edit: Thanks to Warcon, I simply used the reset button as the power switch, and it works flawlessly.

 

[wyvrn]

^^

 

[Dan]

You and your friend will be much further ahead if you buy an ATX case. Since you want to keep costs down, get a:

mid-tower with a 250 Watt power supply from Computer Geeks for $18.95

or a:

Mini-ATX with 300 Watt power supply from American Electronics for $15.

Return the power supply you already have and you shouldn't be out any more money. In fact, you might even wind up a few bucks ahead.

 

[wyvrn]

Well I have one more color figured out. Brown is the positive that activates the switch, but it only stays on for a few seconds. So either the white or blue is the constant positive, I think.


Thanks for the advice, but we are still going to use this case. The cdrom and floppy faceplates are part of the computer bezel, and I don't want to replace them both when we get a new case.

 

[ObiDon]

Just wait until you try to mount the ATX motherboard to the AT motherboard tray! I hope you like Dremels :Q

 

[WarCon]

Does this case use a reset switch? If it does you can use that as the power button and just remove the power switch assembly with the AT supply its attached to. ATX needs a momentary switch. If you can find another old AT case, you could pull the old reset switch out of it and with some moding skill you could rig a mount for it and a spring for the button (the ATX switch had all that built into it). Or you could just mount it in an inconspicuous place and use it as is.

If you cut the wiring from the AT switch and open up the switch box you might be able to convert it to a momentary (shave off the catches) and then wire in a mobo connector to go onto the pins for the power switch. Can't say for sure which color wires are which, but a multimeter or even a probe light should be able to help you figure it out.

 

[WarCon]

I have been planning to do something similar, but now some of the other comments made me look and wow is there a lot of things I would need to cut out. The back plane for connectors and the mounting holes are different. Crap............

Guess I just go ahead and make me a wood case instead or just break down and buy a cheapy.....

 

[Bleep]

The first thing you should do is read very carefully the post made by ObiDon. The motherboard will not fit!!!!
Bleep

 

[ObiDon]

<< Guess I just go ahead and make me a wood case instead >>


That would be sweet! I remember I saw a woodgrain keyboard/mouse set at Fry's once. I don't remember who made it, though. Maybe NEC or Mitsubishi???

 

[wyvrn]

<< The first thing you should do is read very carefully the post made by ObiDon. The motherboard will not fit!!!!
Bleep >>





<< Just wait until you try to mount the ATX motherboard to the AT motherboard tray! I hope you like Dremels >>



Hehehehe! Au contraire! I just mounted the motherboard and switched out the AT plate for an ATX one. Everything already fits, and I knew it would because I measured it ahead of time. The ONLY hangup is the power switch, which I am working on. So far, if with only two connections (ground and positive), the computer will stay on if I click the PS switch twice (on and off within 2 seconds). If I just depress the power switch once, it shuts off after 5 seconds. But I don't want her to have to double press the power switch because it might become aggravating.



<< ATX needs a momentary switch >>



That did it!

 

[WarCon]

Thats cool man. Did you mod the switch to be momentary? Or replace it with a different one?

 

[Bleep]

Well I guess i was wrong on the fit thing, I tried this once and nothing would match up to the pci buss.
sorry my mistake, hope you get it going
Bleep:frown:

 

[wyvrn]

I just used the reset switch for power, as WarCon suggested.

Bleep,

This case had a removable plate in the back, so I was easily able to put in an ATX one. I don't think many AT cases came this way, but luckily this one did. If not for that, I wouldn't have even tried.

 

[ObiDon]

<< This case had a removable plate in the back, so I was easily able to put in an ATX one. I don't think many AT cases came this way, but luckily this one did. >>


I was about to ask that, you lucky bastard!