Thread: P2140 startup/shutdown issues in new carPC

Is it actually starting the hibernation sequence? If it´s not, you probably just don´t have the polarity correct for the motherboard shut-down button line. In addition, with Win7 you usually do have to modify the advanced power management settings for the power button functionality.

If the polarity for the shutdown leads is backwards, it´ll usually get the start-up pulse, but it won´t see the shut-down, and then the PSU will hard-off eventually leading to the conditions you mention. But check your power management first in Win7 to make sure you´ve altered it correctly and saved it.

Eh, just me, but I never really got hibernation, other than saving a few seconds I just prefer it to fully shutdown/startup fresh. *shrug*

Originally Posted by Wayne613

Is it actually starting the hibernation sequence? If it´s not, you probably just don´t have the polarity correct for the motherboard shut-down button line. In addition, with Win7 you usually do have to modify the advanced power management settings for the power button functionality.

If the polarity for the shutdown leads is backwards, it´ll usually get the start-up pulse, but it won´t see the shut-down, and then the PSU will hard-off eventually leading to the conditions you mention. But check your power management first in Win7 to make sure you´ve altered it correctly and saved it.

Eh, just me, but I never really got hibernation, other than saving a few seconds I just prefer it to fully shutdown/startup fresh. *shrug*

Just out of curiosity, why does the polarity matter on what is essentially a momentary switch?

Originally Posted by Wayne613

Is it actually starting the hibernation sequence? If it´s not, you probably just don´t have the polarity correct for the motherboard shut-down button line. In addition, with Win7 you usually do have to modify the advanced power management settings for the power button functionality.

If the polarity for the shutdown leads is backwards, it´ll usually get the start-up pulse, but it won´t see the shut-down, and then the PSU will hard-off eventually leading to the conditions you mention. But check your power management first in Win7 to make sure you´ve altered it correctly and saved it.

Eh, just me, but I never really got hibernation, other than saving a few seconds I just prefer it to fully shutdown/startup fresh. *shrug*

I have it connected via USB, not hardwired into the motherboard. Just seems like the settings arent doing what theyre set to do. And yes Ive updated and saved everything when I change something..

Originally Posted by sebberry

Just out of curiosity, why does the polarity matter on what is essentially a momentary switch?

It´s not the polarity on the switch that matters as your just manually shorting the two to tell it to shut-down or power up. Which is also why putting it backwards for the motherboard itself doesn´t hurt anything, just won´t work properly. It´s just needed for the motherboard connection itself as otherwise it can´t see the shut-down pulse that the carPSU is sending on its own.

As to why exactly, that you will have to ask someone else, as I truly don´t know the exact reason. I looked briefly at the ACPI specifications listed, including the newest 4.0 revision, but still not getting exactly what is being done for the button itself to make the interpretation. This is the way the modern ACPI on/off line has always functioned for the modern power supplies and motherboard interaction though.

Actually in short, a very good question, I´d like to know myself. It did annoy the crap out of me building my own PC in the earlier days, relatively speaking.

Originally Posted by scENFORCER

I have it connected via USB, not hardwired into the motherboard. Just seems like the settings arent doing what theyre set to do. And yes Ive updated and saved everything when I change something..

Ehm...what? There should be a 2 line connection for the ACPI on/off switch. Same as you would for the front power button on a desktop. This gives it the shutdown/startup signals, Green and White for this unit according to what I just gleaned from looking at the manual (section 5.2). Green is the + lead, White is the - for the ACPI on/off on the motherboard.
I think there's a simple jumper that came with the unit to connect to for this, but perhaps you needed to get one of the wiring bundles listed on the cables section of the carnetix site.

Are you using USB wakeup feature in the bios to start it currently? I´m unfamiliar with the 2140, I think your best bet would be hit the Carnetix forums.

If your looking to not have to wire the ACPI line, this stickied thread over there gives details. It will give instructions on how to use the BIOS settings instead, so long as your MB has them. Otherwise you'll have to do what I said before. This is just from a quick look at the manual. Look deeper, as I´m rushing out the door to work now. Look at this thread for an example of what I'm talking about. I also took a quick look at the manual, you need to set JP5 for PC use for the ACPI leads.

Perhaps someone like soundman98 could comment further as I think he´s got experience with the 2140.

^ thanks for the detailed reply. I'll have to go through everything and see whats up, just haven't had the time recently as I am busy with finals.

However, the past two times I've driven the car the PC has randomly shut down about 5-10 minutes in. ..is that a problem I should be concerned with??

Originally Posted by Wayne613

It´s not the polarity on the switch that matters as your just manually shorting the two to tell it to shut-down or power up. Which is also why putting it backwards for the motherboard itself doesn´t hurt anything, just won´t work properly. It´s just needed for the motherboard connection itself as otherwise it can´t see the shut-down pulse that the carPSU is sending on its own.

As to why exactly, that you will have to ask someone else, as I truly don´t know the exact reason. I looked briefly at the ACPI specifications listed, including the newest 4.0 revision, but still not getting exactly what is being done for the button itself to make the interpretation. This is the way the modern ACPI on/off line has always functioned for the modern power supplies and motherboard interaction though.

Actually in short, a very good question, I´d like to know myself. It did annoy the crap out of me building my own PC in the earlier days, relatively speaking.

I'd like to know exactly what happens when the power supply sends the "pulse" to the motherboard.

If you look at the soft power switch connector on any ATX motherboard, one of the pins is grounded, the other isn't. All you need to do is ground the pin that isn't normally attached to ground briefly.

I've started and shut down computers by shorting the two pins together with a screwdriver.


I'm guessing the power supply doesn't simply short the two pins briefly, it must short one to ground. This makes sense - if you have the connector backwards it tries to ground the already grounded pin.

Originally Posted by sebberry

I've started and shut down computers by shorting the two pins together with a screwdriver.

I'm guessing the power supply doesn't simply short the two pins briefly, it must short one to ground. This makes sense - if you have the connector backwards it tries to ground the already grounded pin.

That makes logical sense. And it would explain it. Although, how is it getting the start ¨pulse" then? If you wire ´em wrong the PSU will still start the computer, just won´t see the shut-down. N/m, I think I might understand this now. It´s not actually needing to interpret the start, just shut-down from the + line, as the (car in this case)PSU is acting as the power-button, just simply dragging it down to ground again.

Originally Posted by scENFORCER

However, the past two times I've driven the car the PC has randomly shut down about 5-10 minutes in. ..is that a problem I should be concerned with??

It does have an LED indicator, right? Usually they´ll flash a certain amount of times to give basic codes of what´s going on, and if it´s operating correctly or not. Maybe that it´s just not set up correctly, something´s trying to get more juice then it´s rated for, it´s overheating, no idea really. Might be minor, might not be, from that I really couldn´t say.
I know this is from a sub-set of mp3car, so if you can´t get enough info here and the manual I´d try the direct route to their support mail and give ´em your setup.

Hey guys, so I did some more digging and was able to get my PC to hibernate properly (it no longer does a hard shutdown every other time).
However, now it just doesn't want to wake from hibernate (I have to manually turn it on). According to the P2140 setup video's by Goce, I have to go into BIOS and enable the 'AC PWR Auto Recovery' (the other things outlined in his video are already done). Unfortunately my BIOS doesnt have that option, but it has a buncha other power options which I tried enabling and disabling, to no effect. I've also sent an email to the mp3 support address, hoping they may be able to help.
I haven't switched the polarity yet, was gonna do that Monday evening, but am starting to think this is no longer the solution as the only problem now is waking from hibernation. Seems like its just a setting that I have to change in Windows or the BIOS. Anyways, let me know what you guys think. I am eager to get this working properly finally..

Here are some picture of what my BIOS options look like:

Originally Posted by scENFORCER

However, now it just doesn't want to wake from hibernate (I have to manually turn it on). According to the P2140 setup video's by Goce, I have to go into BIOS and enable the 'AC PWR Auto Recovery' (the other things outlined in his video are already done). Unfortunately my BIOS doesnt have that option, but it

Switch the motherboard on/off ACPI header´s, assuming you hooked this up as stated earlier and assuming you even got a cable for it with the default carnetix psu.

That setting mentioned is for automatically starting after a power loss, the ¨after power loss¨ is what your after for this HP´s bios.