Question about "turning on computer" without a case.

[sdifox]

Okay I got it working in the breadboard with just using batteries for +5v and ground. Light stays on for like 1 second or so then cuts off.

I'm going to keep everything in the breadboard and hook it up to the harnesses I made to hook into the motherboard and PSU and cross my fingers lol.

It should work now xd

 

[Red Squirrel]

Yeah I think the 555 will be the best bet. I kinda was thinking about that before but was not sure how to make it go only once.

 

[purbeast0]

I am so confused now.

I have tried it multiple ways and it appears to be working fine, but the motherboard isn't starting up.

I first tried just just making the +5v and ground from the PSU and the light turned on so that was fine.

I then JUST changed the first +5v to be using the PWRPin but did not hook up the GRDPin so all ground was from PSU and light turned on so that was fine.

I then made pin3 go to GRDPin and nothing happened.

So I then tried hooking the LED back up, and instead of the LED going to ground on the PSU, I hooked up the LED ground to GRDPin and tried that. And the light turned on as usual for about 1 second and then cut off. But, the game did not turn on.

I then tried turning it on manually connecting the 2 pins with a screw (like I always used to manually jump it) and held it there as it turned on, for like 2 seconds And the game did not turn on. Then I tried it again and held it down on there for a shorter time and it turned on.

So maybe the circuit is on too long that it is doing power on and power off? Is there a simple way to make the light on even less time?

EDIT:

I don't know actually I just held down the jumper screw for like 3 seconds and it booted up.

When the pin is jumped initially, you can hear the fan slow down a bit as it boots up. If the motherboard doesn't turn on, the fan stays running faster. With the circuit attached, the fan always stays fast it never slows down.

 

[sdifox]

I am so confused now.

I have tried it multiple ways and it appears to be working fine, but the motherboard isn't starting up.

I first tried just just making the +5v and ground from the PSU and the light turned on so that was fine.

I then JUST changed the first +5v to be using the PWRPin but did not hook up the GRDPin so all ground was from PSU and light turned on so that was fine.

I then made pin3 go to GRDPin and nothing happened.

So I then tried hooking the LED back up, and instead of the LED going to ground on the PSU, I hooked up the LED ground to GRDPin and tried that. And the light turned on as usual for about 1 second and then cut off. But, the game did not turn on.

I then tried turning it on manually connecting the 2 pins with a screw (like I always used to manually jump it) and held it there as it turned on, for like 2 seconds And the game did not turn on. Then I tried it again and held it down on there for a shorter time and it turned on.

So maybe the circuit is on too long that it is doing power on and power off? Is there a simple way to make the light on even less time?

EDIT:

I don't know actually I just held down the jumper screw for like 3 seconds and it booted up.

When the pin is jumped initially, you can hear the fan slow down a bit as it boots up. If the motherboard doesn't turn on, the fan stays running faster. With the circuit attached, the fan always stays fast it never slows down.

So right now you have 1 second based on 10000 Ohm * 0.0001F. Reduce the values of resistor and cap will drop the time.

 

[purbeast0]

So right now you have 1 second based on 10000 Ohm * 0.0001F. Reduce the values of resistor and cap will drop the time.

Ah okay gotcha. That is interesting had no clue about that.

Is there anyway with the stuff I have right now, to delay the circuit from "turning on" so like there would be a 1 second where light is off, 1 where it is on, then it stays off forever? I'm curious to see if it just has something to do with it being "on" as soon as the motherboard turns on.

But then again, that is basically the case when I manually jump it.

In my instance where I have the GNDPin connected after the LED and the LED turns on, that means that the PWRPin and GNDPin are a jumped while that light is on, right?

Or does it just mean the light is on lol?

 

[sdifox]

Ah okay gotcha. That is interesting had no clue about that.

Is there anyway with the stuff I have right now, to delay the circuit from "turning on" so like there would be a 1 second where light is off, 1 where it is on, then it stays off forever? I'm curious to see if it just has something to do with it being "on" as soon as the motherboard turns on.

But then again, that is basically the case when I manually jump it.

In my instance where I have the GNDPin connected after the LED and the LED turns on, that means that the PWRPin and GNDPin are a jumped while that light is on, right?

Or does it just mean the light is on lol?

The circuit is supposed to stay on for one sec then turn off. Is it not doing that?

 

[purbeast0]

The circuit is supposed to stay on for one sec then turn off. Is it not doing that?

Well the light is staying on for 1 second then going off, according to the LED, but it's not turning the motherboard on so I am not sure exactly.

This is when I replace the +5v going to the resistor with the PWRPin and then the ground from the LED with GNDPin.

When I left the LED out of the circuit and just did GNDPin to pin3 of the timer chip it didn't turn it on, just like when I added it to the ground of the LED.

 

[sdifox]

Well the light is staying on for 1 second then going off, according to the LED, but it's not turning the motherboard on so I am not sure exactly.

This is when I replace the +5v going to the resistor with the PWRPin and then the ground from the LED with GNDPin.

When I left the LED out of the circuit and just did GNDPin to pin3 of the timer chip it didn't turn it on, just like when I added it to the ground of the LED.

Ok lets try this.

Replace the current PWRPin and GNDPin with regular +5 and ground.

You mentioned you have relays, let's use the timer output to drive a relay, assuming it is a 5v one.

Wire up the relay's Vcc to 5v and GRD to psu ground. Output of the clock (you can leave the resistor and LED in place) goes to Signal.
PWRPin goes to NO (Normally Open) and PWRGrd to Common.

How to Set Up a 5V Relay on the Arduino

Learn how to set up a 5V relay on the Arduino use sensors to control 120-240V appliances.

www.circuitbasics.com

That explains relay well.

 

[Red Squirrel]

Are you using a transistor or mosfet to activate the relay? The 555 might not be able to do it on it's own so it might be hesitating and then barely making contact. I would also add a small capacitor after the relay in case there's any switch bounce it might help. A smidth(sp?) trigger circuit would be better but that's more complicated to do.

 

[sdifox]

Are you using a transistor or mosfet to activate the relay? The 555 might not be able to do it on it's own so it might be hesitating and then barely making contact. I would also add a small capacitor after the relay in case there's any switch bounce it might help. A smidth(sp?) trigger circuit would be better but that's more complicated to do.

555 shouldn't have problem driving a 5V relay. It is just control, the relay is powered by normal 5VDC. 555 can put out 200 mA max and relay just needs 70 mA.

 

[sdifox]

Actually, before you add the relay, describe how you are testing. Is it just flipping the pc power supply on? Or do you leave the pc psu on, arcade psu on then switch game to this one?

 

[purbeast0]

Actually, before you add the relay, describe how you are testing. Is it just flipping the pc power supply on? Or do you leave the pc psu on, arcade psu on then switch game to this one?

I am just turning on the arcade game, which in turn turns on the ATX PSU via the relay. The arcade PSU has the switch flipped on but I have it plugged into an outlet that I turn on/off via my phone or pushing a button on it. Here's a video actually that I posted the other day trying to trouble shoot another game, and you can see how it turns on.

I have tried it with the ATX plugged into the arcade PSU and also into it's own outlet in standby mode.

 

[sdifox]

I am just turning on the arcade game, which in turn turns on the ATX PSU via the relay. The arcade PSU has the switch flipped on but I have it plugged into an outlet that I turn on/off via my phone or pushing a button on it. Here's a video actually that I posted the other day trying to trouble shoot another game, and you can see how it turns on.

I have tried it with the ATX plugged into the arcade PSU and also into it's own outlet in standby mode.

you said if you short the two pins with a screw driver for a shorter period of time it turns on? Do you have lower value resistor and/or capacitor? Or just have 2 of the 10KOhm resistors and 1 100 uF cap, which should give you 2 seconds.

 

[purbeast0]

you said if you short the two pins with a screw driver for a shorter period of time it turns on? Do you have lower value resistor and/or capacitor? Or just have 2 of the 10KOhm resistors and 1 100 uF cap, which should give you 2 seconds.

Yeah if I just touch the 2 pins together for a second that is how I boot the computer. I don't have any lower value caps or resistors unfortunately. I may actually have an extra capacitor but not sure the rating because it's left over from a capkit.

Actually I do have 2 full capkits that I have not installed that you just reminded me about. It's like 50+ various capacitors. I could look for one in there just to test it out for sure.

So you think I should look for like a 50uf one and see if it works?

 

[sdifox]

Yeah if I just touch the 2 pins together for a second that is how I boot the computer. I don't have any lower value caps or resistors unfortunately. I may actually have an extra capacitor but not sure the rating because it's left over from a capkit.

Actually I do have 2 full capkits that I have not installed that you just reminded me about. It's like 50+ various capacitors. I could look for one in there just to test it out for sure.

So you think I should look for like a 50uf one and see if it works?

well, I just don't know how the interaction plays out between the psus. Because you are using the relay from arcade to control PS-ON, maybe like you said we need to give it a bit of time to stabilise then flick the power switch. So we can try both ways, first try to increase time with adding another 10KOhm resistor giving you 2 sec see if it works, then try the other way, reducing the timer to 1/2 sec by either halving the resistor or the capacitor value.

 

[purbeast0]

well, I just don't know how the interaction plays out between the psus. Because you are using the relay from arcade to control PS-ON, maybe like you said we need to give it a bit of time to stabilise then flick the power switch. So we can try both ways, first try to increase time with adding another 10KOhm resistor giving you 2 sec see if it works, then try the other way, reducing the timer to 1/2 sec by either halving the resistor or the capacitor value.

I just tried the extra resistor and it turned the light on for 2 seconds but no difference. As mentioned I don't hear the fan slow down at all over the whole 2 seconds so it's almost like the pins aren't even being jumped. But they have to be if the light is turning on right? This is getting super frustrating lol. I will try a lower value cap in a bit too just to see if that fixes it.

 

[sdifox]

I just tried the extra resistor and it turned the light on for 2 seconds but no difference. As mentioned I don't hear the fan slow down at all over the whole 2 seconds so it's almost like the pins aren't even being jumped. But they have to be if the light is turning on right? This is getting super frustrating lol. I will try a lower value cap in a bit too just to see if that fixes it.

try measuring the voltage before the resistor+led during those 2 seconds, does it show +5?

 

[purbeast0]

try measuring the voltage before the resistor+led during those 2 seconds, does it show +5?

I'm not sure how to do that on the breadboard as there are no exposed pads really.

I also just tried something where my PWRPin and GNDPin harness literally just connected the other end of the wires together, put it on the pins on the motherboard, and turned the arcade game on.

It starts up with the fan slowly and it's clear that it knows the pins are jumped together.

I kept it on for like a second or two and pulled it off, and the computer stayed on.

So it's like even though the LED is turning on via the PWRPin and GNDPin, it's like the 2 pins still are not connected/jumped while the light is on.

I just tried with a 10uf cap and 1 resistor and see the light on for short time and nothing happens. I tried it with the 100uf and 2 resistors and it's on for the 2 seconds and nothing happens.

Is there any way that the LED could be on but the 2 pins are not jumped still somehow?

 

[purbeast0]

Just tried 47uf cap and same result.

 

[sdifox]

I'm not sure how to do that on the breadboard as there are no exposed pads really.

I also just tried something where my PWRPin and GNDPin harness literally just connected the other end of the wires together, put it on the pins on the motherboard, and turned the arcade game on.

It starts up with the fan slowly and it's clear that it knows the pins are jumped together.

I kept it on for like a second or two and pulled it off, and the computer stayed on.

So it's like even though the LED is turning on via the PWRPin and GNDPin, it's like the 2 pins still are not connected/jumped while the light is on.

I just tried with a 10uf cap and 1 resistor and see the light on for short time and nothing happens. I tried it with the 100uf and 2 resistors and it's on for the 2 seconds and nothing happens.

Is there any way that the LED could be on but the 2 pins are not jumped still somehow?

just add a piece of wire to the same row as the clock output ( 555 pin 3) and measure that against ground.

also try measuring connectivity between PWRPin and the clock output, theoretically it should show +5 for 1 sec (assuming 10KOhm + 100uF) then drop to zero or close to it.

 

[purbeast0]

Okay I measured PWRPin and GNDPin.

When I turn it on it starts like 3.5v or so and grows up to around 5 over the next like 10-15 seconds. Even after the light turns off it keeps growing.

And this is when I am using the GNDPin as the ground for the LED or if I completely remove the LED from the picture and go directly from pin3 to GNDPin.

 

[sdifox]

Okay I measured PWRPin and GNDPin.

When I turn it on it starts like 3.5v or so and grows up to around 5 over the next like 10-15 seconds. Even after the light turns off it keeps growing.

And this is when I am using the GNDPin as the ground for the LED or if I completely remove the LED from the picture and go directly from pin3 to GNDPin.

try measuring the two pins without your circuit and see the behaviour

 

[purbeast0]

try measuring the two pins without your circuit and see the behaviour

So when I put my multimeter to the 2 pins on the motherboard without harness on, it just reads 5.16 and stays there like instantly.

 

[sdifox]

So when I put my multimeter to the 2 pins on the motherboard without harness on, it just reads 5.16 and stays there like instantly.

did the machine turn on when you did that?

also, do you have a 5vdc relay? Might be time to add a relay.

 

[purbeast0]

did the machine turn on when you did that?

also, do you have a 5vdc relay? Might be time to add a relay.

Had to test it again because I didn't even think to check that.

But yes, the game did turn on when I did that.