Question about "turning on computer" without a case.

[sdifox]

Ok can you take two voltage measurement for me?

Shutdown power, wait for cap to drain. start measuring voltage on pin 1 of the xor gate before powering up to see if you get voltage that builds up to 5V.

Then do the same with pin 2, which should be steady 5v the moment you turn it on.

 

[purbeast0]

Ok can you take two voltage measurement for me?

Shutdown power, wait for cap to drain. start measuring voltage on pin 1 of the xor gate before powering up to see if you get voltage that builds up to 5V.

Then do the same with pin 2, which should be steady 5v the moment you turn it on.

I have to put one pin to pin 7 (ground) and then to pin 1 right?

From the picture I showed you, did it look wired up properly?

 

[sdifox]

I have to put one pin to pin 7 (ground) and then to pin 1 right?

From the picture I showed you, did it look wired up properly?

wiring looks right. so two measures are needed. you measure PWRPin and XOR1A Input 1 and then PWRPin and XOR1A Input 2. for the first measure you want to wait til cap is fully drained but hook up the multimeter before you power up.
We want to see the voltage change over time of XPR1A Input1 and confirm that PWRPin is indeed outputting +5VDC.

 

[purbeast0]

I am so confused by these readings.

When I do PWRPin to XOR1 when I power it on I get like .4 mV and it starts to go down

When I do PWRPin to XOR2 I get 0 constantly. It always stays zero.

Then if I do GNDPin to XOR1 or XOR2 it's a constant 5.17v.

I even tried flip flopping the PWRPin and GNDPin and I get the exact readings.

And I am positive that the PWRPin -> XOR2 connection is fine because I have tested it with the connectivity setting on my multimeter.

 

[sdifox]

I am so confused by these readings.

When I do PWRPin to XOR1 when I power it on I get like .4 mV and it starts to go down

When I do PWRPin to XOR2 I get 0 constantly. It always stays zero.

Then if I do GNDPin to XOR1 or XOR2 it's a constant 5.17v.

I even tried flip flopping the PWRPin and GNDPin and I get the exact readings.

And I am positive that the PWRPin -> XOR2 connection is fine because I have tested it with the connectivity setting on my multimeter.

now try between XOR1 and XOR3 and XOR2 and XOR3

 

[purbeast0]

now try between XOR1 and XOR3 and XOR2 and XOR3

Those are both 5.01v

 

[sdifox]

Those are both 5.01v

Can you turn it off, disconnect XOR2, wait a while for cap to drain and then test between XOR1 and XOR3. I am hoping to see 0 then flip to voltage.

 

[purbeast0]

Can you turn it off, disconnect XOR2, wait a while for cap to drain and then test between XOR1 and XOR3. I am hoping to see 0 then flip to voltage.

Just to clarify too, the 5.01v was without me really making sure the cap was drained.

I also thought that adding that resistor would cause the cap to drain since that is what happened on the initial circuit - how come I now have to wait for it to drain?

 

[sdifox]

Just to clarify too, the 5.01v was without me really making sure the cap was drained.

I also thought that adding that resistor would cause the cap to drain since that is what happened on the initial circuit - how come I now have to wait for it to drain?

Just to make sure it is not the cap filling up too fast/ not fully drained when tested.

 

[purbeast0]

Just to make sure it is not the cap filling up too fast/ not fully drained when tested.

Oh okay I gotcha. Okay I'll test it in like 30 minutes just to be sure it's drained.

 

[purbeast0]

So when I turned it on it like jumped to around 4.8v or so and slowly went up to 5v when I removed XOR2 pin and tested between XOR1 and XOR3. But the LED never came on or anything still and it didn't turn the computer on.

 

[sdifox]

So when I turned it on it like jumped to around 4.8v or so and slowly went up to 5v when I removed XOR2 pin and tested between XOR1 and XOR3. But the LED never came on or anything still and it didn't turn the computer on.

So there is no delay of any sort? Add another resistor

 

[purbeast0]

So there is no delay of any sort? Add another resistor

Add the resistor where? Before the first resistor?

 

[sdifox]

Add the resistor where? Before the first resistor?

Yeap, doubling up on resistor should slow it down.

 

[purbeast0]

Yeap, doubling up on resistor should slow it down.

Inline or parallel?

 

[sdifox]

Inline or parallel?

Inline

 

[purbeast0]

So I'm noticing something now that I didn't know before.

I had the ATX PSU plugged into another outlet and was testing it that way. I would turn the ATX PSU on (with the switch, but it didn't actually "turn on" until I turn the arcade game on) and it would be in standby mode and I saw no LED coming on.

I now have it hooked to the arcade PSU and the "switch gets flipped" when the arcade turns on, and then the ATX PSU also "turns on" when it starts up. And I'm now seeing the LED flash quickly initially. But if I turn the game off and back on, the LED doesn't flash at all.

Also, the game isn't turning on. The LED is staying on really short, like shorter than it was with the circuit 1 before it started pulsing.

I'm just about giving up on this and feel defeated lol. I think the first circuit was closer because it was actually doing the job, but it like kept trying to do it and that is why it was pulsing I believe (coudl be wrong about that). It also seems like the cap is not discharing on circuit 2 like it was on the first one because when I try stuff a second time, the LED doesn't come on which I'm guessing is because cap isn't discharged yet.

Adding an extra resistor just now in line made no difference. So it's now going PWRPin -> resistor -> resistor -> XOR1 and it's the same as it was before without the extra resistor.

 

[sdifox]

So I'm noticing something now that I didn't know before.

I had the ATX PSU plugged into another outlet and was testing it that way. I would turn the ATX PSU on (with the switch, but it didn't actually "turn on" until I turn the arcade game on) and it would be in standby mode and I saw no LED coming on.

I now have it hooked to the arcade PSU and the "switch gets flipped" when the arcade turns on, and then the ATX PSU also "turns on" when it starts up. And I'm now seeing the LED flash quickly initially. But if I turn the game off and back on, the LED doesn't flash at all.

Also, the game isn't turning on. The LED is staying on really short, like shorter than it was with the circuit 1 before it started pulsing.

I'm just about giving up on this and feel defeated lol. I think the first circuit was closer because it was actually doing the job, but it like kept trying to do it and that is why it was pulsing I believe (coudl be wrong about that). It also seems like the cap is not discharing on circuit 2 like it was on the first one because when I try stuff a second time, the LED doesn't come on which I'm guessing is because cap isn't discharged yet.

Adding an extra resistor just now in line made no difference. So it's now going PWRPin -> resistor -> resistor -> XOR1 and it's the same as it was before without the extra resistor.

oh, I was assuming you had it hooked up to arcade psu since it was sending signal through the relay to the PC PSU. Leave the Arcade one on, just use the physical switch of the PC PSU.

this is not supposed to be so hard lol. Add a cap in parallel to the first cap. Make sure the polarity is the same. That in theory should double the amperage of the cap thus making it take longer to charge.

 

[purbeast0]

oh, I was assuming you had it hooked up to arcade psu since it was sending signal through the relay to the PC PSU. Leave the Arcade one on, just use the physical switch of the PC PSU.

this is not supposed to be so hard lol. Add a cap in parallel to the first cap. Make sure the polarity is the same. That in theory should double the amperage of the cap thus making it take longer to charge.

Regardless of the ATX being hooked up to the arcade PSU or to another outlet, the arcade is turning it "on". If I flip the switch on and it's hooked up to an outlet, it's just in stand by mode until the arcade cabinet is turned on.

It's tough for me to just keep re-routing stuff because I cut the legs off of the caps/resistors so their isn't much wiggle room. I had to add wires to one of my resistors to get it to fit physically on the board lol.

I am still not getting why with the circuit 2 the caps are not discharging on their own, but on circuit 1 they were. Well I think it was because of the resistor after but not really sure. Circuit 2 doesn't have that and they don't discharge, but I thought that we wanted it to discharge?

I feel like I'm going in circles now lol.

 

[sdifox]

Regardless of the ATX being hooked up to the arcade PSU or to another outlet, the arcade is turning it "on". If I flip the switch on and it's hooked up to an outlet, it's just in stand by mode until the arcade cabinet is turned on.

It's tough for me to just keep re-routing stuff because I cut the legs off of the caps/resistors so their isn't much wiggle room. I had to add wires to one of my resistors to get it to fit physically on the board lol.

I am still not getting why with the circuit 2 the caps are not discharging on their own, but on circuit 1 they were. Well I think it was because of the resistor after but not really sure. Circuit 2 doesn't have that and they don't discharge, but I thought that we wanted it to discharge?

I feel like I'm going in circles now lol.

well the relay is what tells the PC PSU that it is hooked up to a mb and it is safe for it to power up.

Ground connection is always there so the cap will discharge, albeit slower than having a resistor after it. you can just solder a piece of wire to the leg, no biggie.

 

[purbeast0]

So if I add another cap in parallel (only have one other one lol) should I also keep XOR2 with no PWRPin going to it? Or should I connect that back?

 

[sdifox]

So if I add another cap in parallel (only have one other one lol) should I also keep XOR2 with no PWRPin going to it? Or should I connect that back?

no, you need the PWRPin feeding it, adding another cap is just to increase the charge time, hoping to be long enough before it turns XOR3 to off.

 

[purbeast0]

no, you need the PWRPin feeding it, adding another cap is just to increase the charge time, hoping to be long enough before it turns XOR3 to off.

Okay I will give that a try because that won't take much time lol.

 

[purbeast0]

I added the cap and the light stays on for like 1/4 second maybe when it powers on, however it still doesn't start up the motherboard. This is super frustrating lol.

The cap definitely made a difference as far as how long the light stayed on.

 

[sdifox]

I added the cap and the light stays on for like 1/4 second maybe when it powers on, however it still doesn't start up the motherboard. This is super frustrating lol.

The cap definitely made a difference as far as how long the light stayed on.

ok, so now disconnect the cap and led from XOR pin 3 and wire XOR Pin 3 to the PWRPin's GRD.