Question about "turning on computer" without a case.

[Red Squirrel]

I wonder if the motherboard does not like the fact that the PSU is being turned on and the power switch was not hit so it acts differently? One thing you could try, is hook up the relay in such a way that it only turns on momentarily, then hook it up to the power switch header. Then it would be like turning on the computer normally. I can't think of a proper analog circuit for that off the top of my head, but I don't imagine it would be too hard to do. Another option is to use a microcontroller that handles the turning on of everything, so pushing the power switch turns on the microcontroller and it turns on the appropriate relays to turn on what you need. For the computer it would just turn the relay on/off once. To reset you would turn on the main power switch, but could also have a separate reset button.

 

[purbeast0]

I wonder if the motherboard does not like the fact that the PSU is being turned on and the power switch was not hit so it acts differently? One thing you could try, is hook up the relay in such a way that it only turns on momentarily, then hook it up to the power switch header. Then it would be like turning on the computer normally. I can't think of a proper analog circuit for that off the top of my head, but I don't imagine it would be too hard to do. Another option is to use a microcontroller that handles the turning on of everything, so pushing the power switch turns on the microcontroller and it turns on the appropriate relays to turn on what you need. For the computer it would just turn the relay on/off once. To reset you would turn on the main power switch, but could also have a separate reset button.

I think if I have something hooked up to the PWRSW then I don't need to do anything else since that would be essentially like hitting the legit power button. Although, I do still want it to turn off the PSU so maybe I would need something else.

 

[lxskllr]

Know what would be cool? Put an automotive key ignition on the front, and wire it to the mb and power supply. On position energizes the psu, and start hits the momentary switch to turn it on :^D

Edit:
I'm semi serious btw. If you didn't want an automotive switch, I bet someone makes a 3 position where the 3rd is momentary.

 

[sdifox]

I think if I have something hooked up to the PWRSW then I don't need to do anything else since that would be essentially like hitting the legit power button. Although, I do still want it to turn off the PSU so maybe I would need something else.

How was this particular game hooked up when it was in a cabinet by itself?

 

[purbeast0]

How was this particular game hooked up when it was in a cabinet by itself?

It never was. I'm currently trying to find out how it is though when it's in a dedicated cabinet. I think there is this other harness that plugs into the PSU that has a little PCB connected to it and then that connects to the power switch or reset pins.

 

[purbeast0]

You can actually kind of see the dongle here I am referring to. I am guessing that is what does it maybe? Still trying to see if someone can confirm though but the arcade forums are slower than ATOT so may take a day or two hopefully.

 

[purbeast0]

Here are a few more pics of that watchdog harness from someone else.

Looking at timer relays on ebay, I wonder if that is actually just a timer relay.

 

[mopardude87]

Make sure its at least grounded. I use usually a motherboard box with a anti static bag laid down. Done builds like this on a budget for friends mentioning the risks involved but usually they don't mind. They had cats, like a bunch of them. They love computers usually. Later on i get a case and i just put their rig in it. Sometimes my own if a mood catches me to build something out of spare parts. I like recycling pc parts whenever i can.

My htpc is in a Emachines case circa 2004. 2500k and a 660 isn't much and its got a 80mm fan cooling off the rig just fine. That 2500k is so awesome for a cpu i bought back in 2011.

About to turn this old Dell with a i3 2100 into a Windows xp retro gaming box. I got a like brand new 20 hours or so powered on gtx285. Old games like BF2/CS1.6 hardly stress the gtx285 so the stock oem psu will be fine with a adapter. Gonna have to rig up a new cover as the gtx285 is not low profile, i got tons of boxes here next to me hmm.

https://www.newegg.com/white-monoprice-0-67-ft-others/p/0ZF-002C-00005?Item=9SIA4B04RX6631 dual sata to 6 pin. Oh yeah its gonna happen for sure now, been on the mind a while but was not sure if such a adapter existed. Realized the htpc 660 will have to go into retro box, cause the oem psu only has 2 spare sata cables. Might be best, it uses a ton less energy anyways over a 285.

 

[sdifox]

Make sure its at least grounded. I use usually a motherboard box with a anti static bag laid down. Done builds like this on a budget for friends mentioning the risks involved but usually they don't mind. They had cats, like a bunch of them. They love computers usually. Later on i get a case and i just put their rig in it. Sometimes my own if a mood catches me to build something out of spare parts. I like recycling pc parts whenever i can.

My htpc is in a Emachines case circa 2004. 2500k and a 660 isn't much and its got a 80mm fan cooling off the rig just fine. That 2500k is so awesome for a cpu i bought back in 2011.

About to turn this old Dell with a i3 2100 into a Windows xp retro gaming box. I got a like brand new 20 hours or so powered on gtx285. Old games like BF2/CS1.6 hardly stress the gtx285 so the stock oem psu will be fine with a adapter. Gonna have to rig up a new cover as the gtx285 is not low profile, i got tons of boxes here next to me hmm.

https://www.newegg.com/white-monoprice-0-67-ft-others/p/0ZF-002C-00005?Item=9SIA4B04RX6631 dual sata to 6 pin. Oh yeah its gonna happen for sure now, been on the mind a while but was not sure if such a adapter existed. Realized the htpc 660 will have to go into retro box, cause the oem psu only has 2 spare sata cables. Might be best, it uses a ton less energy anyways over a 285.

What are you on about?

 

[mopardude87]

What are you on about?

Getting the most out of computers?

 

[sdifox]

Getting the most out of computers?

Start your own thread

 

[sdifox]

Here are a few more pics of that watchdog harness from someone else.

Looking at timer relays on ebay, I wonder if that is actually just a timer relay.

I cannot tell what that thing is lol. But I think I have a simple solution, just need to draw it. Not at computer right now. No need for timer relay.

 

[purbeast0]

Okay so I have some new discoveries...

Here is a pic of the setting that I thought would turn the computer on when the ATX PSU gets power, sorry for the crappy pic but it's on a CRT when the resolution hasn't synced up.

I just removed the relay and hooked the PSU back up to default.

With that setting turn on, if I manually flip the switch on my PSU, the motherboard turns on and the game boots up.

Could the problem be that since I cut off the green switch wire of the ATX PSU and routed it to the relay instead, that could be making it not work? Like I didn't run a wire back from the relay pin back to the green wire that plugs into the molex plug into the motherboard. Could that be what is causing it not to turn on?

I could very easily try it out but I also don't want to fry anything since I don't know enough about relays that routing the green wire from PSU -> relay -> motherboard could do any damage.

 

[zinfamous]

What are you on about?

His indica, duh.

 

[mopardude87]

Start your own thread

Will think about it, just shared some excitement was all. You're ignored, you been constantly up my ass on about every post you can find to nick pick at. Be safe when you go out ok?

Edit: that was my one and only post i planned on posting, till you got on my case AGAIN.

 

[DAPUNISHER]

With that setting turned on, if I manually flip the switch on my PSU, the motherboard turns on and the game boots up.

That's because you killed power to the board when turning the PSU off. As long as the board gets power i.e. any LEDs on the board are lit, that setting should not turn the system on. The real time clock will turn it on at a specific time, which is not what you are trying to do. I was hoping we could use the PCI or PS/2 function, but that should only work from sleep or hibernation.

 

[sdifox]

Okay so I have some new discoveries...

Here is a pic of the setting that I thought would turn the computer on when the ATX PSU gets power, sorry for the crappy pic but it's on a CRT when the resolution hasn't synced up.

I just removed the relay and hooked the PSU back up to default.

With that setting turn on, if I manually flip the switch on my PSU, the motherboard turns on and the game boots up.

Could the problem be that since I cut off the green switch wire of the ATX PSU and routed it to the relay instead, that could be making it not work? Like I didn't run a wire back from the relay pin back to the green wire that plugs into the molex plug into the motherboard. Could that be what is causing it not to turn on?

I could very easily try it out but I also don't want to fry anything since I don't know enough about relays that routing the green wire from PSU -> relay -> motherboard could do any damage.

flip the switch as in turn the power supply on right?

Turn a Computer Power Supply into Bench Power | Make:

This design for an external adapter lets you use a computer power supply without modifying it.

makezine.com

are we talking about that green Pin 16 on the 24 pin psu output?
you need to hook that green wire back to the way a normal computer is.

what do the white words say?

 

[purbeast0]

That's because you killed power to the board when turning the PSU off. As long as the board gets power i.e. any LEDs on the board are lit, that setting should not turn the system on. The real time clock will turn it on at a specific time, which is not what you are trying to do. I was hoping we could use the PCI or PS/2 function, but that should only work from sleep or hibernation.

Well actually I am kind of trying to do that.

So my arcade PSU has a port in it that I want to basically daisy chain my ATX PSU onto, so that it only is getting any power once the cabinet is on. When the power is off it would be getting no power at all.

However, when I daisy chain my ATX PSU to the arcade PSU, I am getting screen interference and I really don't know why. When I plug the ATX PSU into the wall I don't get any screen interference, but then you are right in that the board would still be getting power when it is off.

 

[purbeast0]

flip the switch as in turn the power supply on right?

Turn a Computer Power Supply into Bench Power | Make:

This design for an external adapter lets you use a computer power supply without modifying it.

makezine.com

are we talking about that green Pin 16 on the 24 pin psu output?

Yes to both.

 

[purbeast0]

Here's a picture of the relay for clarification too. I just wired up terminals so I can do quick disconnects.

Those terminals go to the ground and +12v coming from the interface board.

Then that green wire is the green 16 pin from the ATX PSU and note there is nothing that goes back to the other side of that wire I cut onto the PSU.

The other black wire is going to a ground wire coming from the ATX PSU.

Are you saying I should run another wire from that green pin on the relay to the green wire that is going to the 24pin molex connector? Because as of now, there is nothing going to that pin on the molex connector, it's just the other side of the empty/cut wire.

 

[purbeast0]

Well actually I am kind of trying to do that.

So my arcade PSU has a port in it that I want to basically daisy chain my ATX PSU onto, so that it only is getting any power once the cabinet is on. When the power is off it would be getting no power at all.

However, when I daisy chain my ATX PSU to the arcade PSU, I am getting screen interference and I really don't know why. When I plug the ATX PSU into the wall I don't get any screen interference, but then you are right in that the board would still be getting power when it is off.

@DAPUNISHER I actually stand corrected on this.

I just tried hooking the ATX PSU up to my arcade PSU and it acts the same way it does when plugged into the wall and in "stand by" mode even when off. I still have to jump it.

 

[sdifox]

@DAPUNISHER I actually stand corrected on this.

I just tried hooking the ATX PSU up to my arcade PSU and it acts the same way it does when plugged into the wall and in "stand by" mode even when off. I still have to jump it.

ok looks like when the Arcade PSU gets power, the relay activates and signals the PC PSU that it is hooked up to a load, so you need to "press" the power button to turn on PC.

Something like this.




A is the power button pin that has the +5 VDC, check your manual on which one that is. B is the other pin.

when the PC MB is powered on, A receives +5 VDC. the 2 input for the XOR gate would read 0 (pin 1) and 1 (pin 2), output (3) becomes 1.
This will supply power to the B pin and the second path with the resistor, capacitor and base of transistor.
After a bit more than a second of 3 getting power, the transistor will turn on allowing connection between transistors pin 2 and 3, making input 1 to XOR gate 1 and 1. This in turn put output of XOR to 0.

The RC (resistor capacitor) delay is about 1 second.


That ought to do it.

 

[purbeast0]

ok looks like when the Arcade PSU gets power, the relay activates and signals the PC PSU that it is hooked up to a load, so you need to "press" the power button to turn on PC.

Something like this.

View attachment 22418


A is the power button pin that has the +5 VDC, check your manual on which one that is. B is the other pin.

when the MB is powered on, A receives +5 VDC. the 2 input for the XOR gate would read 0 (pin 1) and 1 (pin 2), output (3) becomes 1.
This will supply power to the B pin and the second path with the resistor.
Given x time (depending on resistor value) the transistor will turn on allowing connection between transistors pin 2 and 3, making input 1 to XOR gate 1 and 1. This in turn put output of XOR to 0.

The RC (resistor capacitor) delay is about 1 second.


That ought to do it.

I appreciate the diagram but I'd be lying if I understood anything you just said lol. This stuff is completely foreign to me. Are you saying I need to make some little adapter like you have there diagrammed, that is between pins A and B ?

Also do you think if I ran the green wire above back to the molex connector that it might solve this? You mentioned "hook the green wire back to the way it was" but I wasn't sure exactly what you meant by that. As shown in my diagram above, the green wire does not make it's way back to the molex connector after connecting to the relay.

 

[sdifox]

I appreciate the diagram but I'd be lying if I understood anything you just said lol. This stuff is completely foreign to me. Are you saying I need to make some little adapter like you have there diagrammed, that is between pins A and B ?

Also do you think if I ran the green wire above back to the molex connector that it might solve this? You mentioned "hook the green wire back to the way it was" but I wasn't sure exactly what you meant by that. As shown in my diagram above, the green wire does not make it's way back to the molex connector after connecting to the relay.

ignore the connect green wire back comment, it is just my misunderstanding. The relay you glued on the board is doing its job, you just leave your PC PSU switch to on position.

It's a very simple circuit involving a resistor, a capacitor, a XOR logic gate and a PNP transistor. But if it is beyond you then a button switch it is

 

[purbeast0]

ignore the connect green wire back comment, it is just my misunderstanding. The relay you glued on the board is doing its job, you just leave your PC PSU switch to on position.

It's a very simple circuit involving a resistor, a capacitor, a XOR logic gate and a PNP transistor. But if it is beyond you then a button switch it is

I would definitely like to do this without a switch if possible. And doing this kind of stuff is fun to me.

So those parts you are talking about, is that something I'd have to order from like digikey or something? Would I have to get some small empty breadboard or something to hook it all to?

EDIT:

Do you know if this is stuff Microcenter sells in the DIY section, if you are familiar with the store? I have one local.

EDIT 2:

Looks like they have capacitors, resistors, and the transistor. I don't really know what the XOR logic gates are I just keep getting these chips with like 16 legs when I search for em, but your diagram only shows 3 pins. Can you point me to one of those? Here are the parts I found at Microcenter, would these work?

PNP transistor - https://www.microcenter.com/product...-pnp-audio-amplifier-switch-transistor-5-pack

Capacitor - https://www.microcenter.com/product...c10-0060-100uf-16v-radial-capacitors---2-pack

Resistor - https://www.microcenter.com/product/390039/nte-electronics-1-4-watt-10k-ohm-resistor-4-pack

There were multiple results for 100uf caps though so I wasn't sure if they will all work or not.