Question ATX 24pin to Xbox 12 pin

Cole.perera

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I have a original Xbox (rev 1.0) with a dead PSU. I also have a few ATX computer PSUs lying around I looked at the wireing diagrams for both and it looks like I can get all the needed voltages from the 24pin connector.

Would this work or just spark and explode in my face, I can splice wires together but have never tried this before. I know I'd have to bridge the pins to turn on the PSU as well.
 

Eximo

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Should be fine as long as you wire it up correctly.
Though I don't see a reason you couldn't find a used Xbox supply on the cheap.

On older ATX power supplies they do have a flaw if there is an unbalanced load. For example all 12V and no 5V load can cause odd behavior and result in very high 12V output or huge transients. More recent single rail supplies typically don't have this problem since they tend to use DC-DC converters to make 5V.

I once hotwired a game cube with an ATX supply. Ran on only 5V at something ludicrous like 80 Amps. Eventually blew up the power supply, but it was neat.
 

jonnyguru

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I have a original Xbox (rev 1.0) with a dead PSU. I also have a few ATX computer PSUs lying around I looked at the wireing diagrams for both and it looks like I can get all the needed voltages from the 24pin connector.

Would this work or just spark and explode in my face, I can splice wires together but have never tried this before. I know I'd have to bridge the pins to turn on the PSU as well.
ATX power supplies don't have +3.3VSB. They have +5VSB. You're going to need a buck converter of sorts to buck that +5VSB down to +3.3V.

On older ATX power supplies they do have a flaw if there is an unbalanced load. For example all 12V and no 5V load can cause odd behavior and result in very high 12V output or huge transients. More recent single rail supplies typically don't have this problem since they tend to use DC-DC converters to make 5V.

I once hotwired a game cube with an ATX supply. Ran on only 5V at something ludicrous like 80 Amps. Eventually blew up the power supply, but it was neat.
I know a guy who uses the cheapest ATX power supplies he can find to power the +12V for his 3D Printer. They blow up often. I keep telling him that if he got a better PSU in the first place, it would cost more initially, but less in the long run. But he doesn't listen.
 

Eximo

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Don't see why you couldn't just run 3.3 volts into the pin. The standby part is just what it would get when powered off. In this situation you would be forcing it on anyway to get the voltages.

The safest route is still to buy a used power supply.
 
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jonnyguru

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Don't see why you couldn't just run 3.3 volts into the pin. The standby part is just what it would get when powered off. In this situation you would be forcing it on anyway to get the voltages.
That should work. I honestly don't know what an X-Box does with standby power.

If you didn't have a +5VSB on your PC, you would eventually lose your BIOS settings and none of the wake functions would work.
 
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Cole.perera

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ATX power supplies don't have +3.3VSB. They have +5VSB. You're going to need a buck converter of sorts to buck that +5VSB down to +3.3V.



I know a guy who uses the cheapest ATX power supplies he can find to power the +12V for his 3D Printer. They blow up often. I keep telling him that if he got a better PSU in the first place, it would cost more initially, but less in the long run. But he doesn't listen.
Ok, so since the 3.3V is only needed for standby I can omit it right? I don't need standby I only want it to run.
 

Cole.perera

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That should work. I honestly don't know what an X-Box does with standby power.

If you didn't have a +5VSB on your PC, you would eventually lose your BIOS settings and none of the wake functions would work.
I need 3.3V for the orange pin but the standby power is 1.2 V, how would I get 3.3V from something? Resisters?
Would Power On be equivalent to the green pin on a ATX PSU?
 

Eximo

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Umm, voltage to voltage. Don't try going and mixing function into it.

You should have 12V+, 5V+ and 3.3V+ on your ATX power supply. That is all I see on the diagram I found.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=2ahUKEwiPvryrnNDjAhWKGs0KHcApA7QQjRx6BAgBEAU&url=http://assemblergames.com/threads/original-xbox-power-supply-mod.69401/&psig=AOvVaw1sm29jn4drmETSHv4GCkyR&ust=1564149276501804

Wire it up for the power ON state I would think, you would need to short the ATX power supply 5V+ standby to ground to keep it on. The Xbox is just going to see the voltages. It will either just turn on or you will still have to press the power button.
 

jonnyguru

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Ok, so since the 3.3V is only needed for standby I can omit it right? I don't need standby I only want it to run.
No. Don't omit it. Just wire +3.3V to it. All I'm saying is it won't be live when the X-box is "off".

I need 3.3V for the orange pin but the standby power is 1.2 V, how would I get 3.3V from something? Resisters?
Would Power On be equivalent to the green pin on a ATX PSU?
You don't need 1.2V. And the power on should be the same as an ATX PSU.
 

Cole.perera

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No. Don't omit it. Just wire +3.3V to it. All I'm saying is it won't be live when the X-box is "off".



You don't need 1.2V. And the power on should be the same as an ATX PSU.
On the diagram I found it says 3.3v (1.2v in rev 1.0)
I have rev 1.0 so I'm assuming I need 1.2v for standby.
 

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