Thread: DCDC USB Power Switch

try reversing the wires SNO

Well all I get now is a quick pulse of on. And it quickly shuts back off.
Push-down time is set to 400msec

EDIT:
I think I have it booting but once the IGN is lost I'm not getting the power button push.
Nor am I getting the PowerSwitch press when i use the DCDC USB software and i hit the power switch button.
Thanks again!

A few possibilities here, so probably best to check everything:

1. If you have the PC PSU connected to the DC-DC output, it may be drawing too much power and cause the DC-DC to shutdown.
2. If the PC PSU is connected directly to 12V, is the 12V+ direct to battery, or a 12V ignition source that might not be reliable?
3. Is the PC PSU actually capable of providing sufficient power for your PC?
4. Is the heatsink/fan securely attached to the CPU?
5. When you go ignition on, does the DC-DC PSU power up and stay on.

If you are using a DC-DC PSU in conjuction with another carPC PSU like an M2-ATX or something similar, remember that you have to have an ignition wire to THAT PSU as well as the DC-DC unit, or it won't latch "ON" when you turn the key. Of course, if you are using a standard carPC PSU, then you might as well use the startup signal from it rather than the DC-DC PSU.

Probably re-stating the obvious here, but who knows?

VegasGuy

I have dcdc-usb. Does it work ok in the "dumb" mode? Make sure that the last two jumpers are not set. This way, IGN line will be ignored and you only need 12V and ground. Does it work ok then? I think in the dumb mode, dcdc-usb will send a power-on signal to the mobo as soon as it gets power, but it shouldn't shut down after 5 seconds (or at all, for that matter)

Originally Posted by VegasGuy

A few possibilities here, so probably best to check everything:

1. If you have the PC PSU connected to the DC-DC output, it may be drawing too much power and cause the DC-DC to shutdown.
2. If the PC PSU is connected directly to 12V, is the 12V+ direct to battery, or a 12V ignition source that might not be reliable?
3. Is the PC PSU actually capable of providing sufficient power for your PC?
4. Is the heatsink/fan securely attached to the CPU?
5. When you go ignition on, does the DC-DC PSU power up and stay on.

If you are using a DC-DC PSU in conjuction with another carPC PSU like an M2-ATX or something similar, remember that you have to have an ignition wire to THAT PSU as well as the DC-DC unit, or it won't latch "ON" when you turn the key. Of course, if you are using a standard carPC PSU, then you might as well use the startup signal from it rather than the DC-DC PSU.

Probably re-stating the obvious here, but who knows?

VegasGuy

Thanks for the reply.
I should have said nettop instead of PC. It accepts 19v DC which is what I have the DCDC USB set to put out.

1. DCDC USB doesn't shutdown LED and voltage show fine.
2. Currently hooked up in the house to a psu that output 19vdc.
3. Not an issue.
4. Atom mobo/Fanless
5. Yes.

Originally Posted by nivanov

I have dcdc-usb. Does it work ok in the "dumb" mode? Make sure that the last two jumpers are not set. This way, IGN line will be ignored and you only need 12V and ground. Does it work ok then? I think in the dumb mode, dcdc-usb will send a power-on signal to the mobo as soon as it gets power, but it shouldn't shut down after 5 seconds (or at all, for that matter)

In dumb mode the switch doesn't get turned on at all, but if i hit the power button on the PC it works fine.

So after taking a multimeter to this the psw on the dcdc usb isn't doing anything. Even when i set the push down to 5 sec my multimeter shows no voltage change or anything.

Originally Posted by windex

Thanks for the reply.
I should have said nettop instead of PC. It accepts 19v DC which is what I have the DCDC USB set to put out.

1. DCDC USB doesn't shutdown LED and voltage show fine.
2. Currently hooked up in the house to a psu that output 19vdc.
3. Not an issue.
4. Atom mobo/Fanless
5. Yes.

[EDIT] So there you go....bad startup controller.

Well then, you're screwed! (just kidding...I always wanted to type that)


If you're satisfied that the DC-DC PSU is putting out the correct voltage and is able to handle the load, then remove the startup/shutdown pulse from the equation. You should be able to short the motherboard pins to simulate startup/shutdown pulse from the DC-DC unit. Does the nettop continue to run in that scenario? If so, then the DC-DC unit is sending multiple pulses or something that causes the motherboard to shutdown. If not, and you're SURE the DC-DC unit is providing the correct power, then there's something amiss on the motherboard. loose RAM? All connectors in place where they should be?

Do you see any of this behavior when you're powered up in the house?

VegasGuy

Originally Posted by VegasGuy

Well then, you're screwed! (just kidding...I always wanted to type that)


If you're satisfied that the DC-DC PSU is putting out the correct voltage and is able to handle the load, then remove the startup/shutdown pulse from the equation. You should be able to short the motherboard pins to simulate startup/shutdown pulse from the DC-DC unit. Does the nettop continue to run in that scenario? If so, then the DC-DC unit is sending multiple pulses or something that causes the motherboard to shutdown. If not, and you're SURE the DC-DC unit is providing the correct power, then there's something amiss on the motherboard. loose RAM? All connectors in place where they should be?

Do you see any of this behavior when you're powered up in the house?

VegasGuy

Yea i can just short the wires i soldered on the power button and the nettop operates normally. So It's def the dcdc usb thats being stupid.