FAQ: How do I power my DC-DC PSU on my workbench? - Page 2

long.1 · 07-25-2007, 01:52 PM

Quote: Originally Posted by 2k1Toaster

I have never heard of the 8-9......

Quote: Originally Posted by vladcarpc

Yes, it works without pin 8 and 9...... In my workbench I tested with and without pins 8 and 9 and there is no difference so far.

I've also been trying this setup over the last few weeks, and I've found that shorting pins 8 & 9 makes no difference. Likewise, I've been getting low voltages, and I'm yet to get things to work consistently. For others that may be interested, my experiences including photos are in the following thread:
Testing Opus 150 via ATX - Computer is Continually Rebooting.

Cheers,

Long.1

angrycamel · 07-25-2007, 10:21 PM

Thanks to everyone for the input. I have made progress, but first a little recap and clarification on the topic...

If the lowered voltage (9.45) on the 12 volt rail of my power supply is caused by a short, I cannot see it in the external wires. I double checked what the voltage level was directly at the 20 pin connector (unsure what that is called), and I got the same 9.45 reading.

The power supply is labeled as +12V on the yellow wire also stating 9A (see the image below). It was pulled, temporarily, out of a "functional" Gateway PC I have in the basement running as a file server. Also, I double checked the condition of the wires and all of them up to the metal casing are good with no cuts or anything like that. So I can only assume the short that causes the lowered voltage is on the inside of the PS casing. So I can only assume that there must be a problem with the internals of the power supply. Can anyone offer any insight in that regard? Have you experienced the same symptoms and found a workaround or repair for the power supply?

The label of the power supply that does not work (putting out 9.45V rather than the 12V it states):

Now for the good news...
I had another power supply lying around that came with the IBM Netvista case that I bought off of Ebay. I jumped the 8-9 pins just as with the other one, then powered it up to test the voltage level coming form the 20 pin connector's yellow wire. It was showing 11.55 (see the second image below). Using the exact same setup that had failed to work with the other power supply, I was able to jump the white ignition wires, once it was all hooked up, and the computer booted!

So...
Thanks for helping out and posting such great tutorials! You guys rock! I hope documenting my troubles will help to show others that (with the M2-ATX at least) you need to have over 9.45V supplied before it will boot the computer. That very well may be in the documentation for the M2-ATX, but... "I was hired to lead, not read."

FYI: I had pulled out both jumpers during my tests as well and I can confirm too that the 13-14 pin jumper is the only required one.

dyne · 08-13-2007, 11:51 AM

Oh, for all the people fiddling with wires to short the green with a ground wire:

Just use a big paperclip. Clip it up so you end up with one 'U' shaped piece of metal, and stick them in the pins of the connector. It'll stay in much more securely than shoving a wire in there.

salvi · 08-24-2007, 11:56 AM

I use a paper clip and it works. The weird thing is that the PC is turning on without the Ignition wire being connected. Since I didn't have a switch, I just left them disconnected and would connect/disconnect them to simulate the switch. Well, I only had the Ground/Power connected and once I turn the PSU on, the PC turns on as well. Any ideas why this is happening? I'm using the M1.

2k1Toaster · 08-24-2007, 12:01 PM

Your BIOS is set to turn on after a power failure. usually there is on/off/last state as options.

salvi · 08-24-2007, 02:26 PM

Hmm, I'll check that setting. I thought that the PSU was the one that controlled the on/off via the ignition cable?

2k1Toaster · 08-24-2007, 02:32 PM

Quote: Originally Posted by salvi

Hmm, I'll check that setting. I thought that the PSU was the one that controlled the on/off via the ignition cable?

Yes. It controls on and off from the ignition line status. This option is in the BIOS for computers in a house/business. If the power goes out, and then comes back on, do you want the computer to come on, stay off, or return to the last known state.

In the car, if you didnt have a smart DC-DC, and had it set to ON after power failure, and the power relay tripped by the accessory wire, it will start but from a cold boot every time, and it would pull the plug when the engine dies. Not shut down the PC, but yank out the cord.

So every time the key goes from off to on, the computer must cold boot because there is not power for Standby, and both hibernate and standby would require you to press a button to bring it out of that state. The BIOS settings only work for when it is a cold boot.

salvi · 08-24-2007, 04:13 PM

I was just confused since I'm using the M1 on the workbench. With my SP13000 this must not have been enabled. I'll disable this setting and hopefully it works like a charm.

salvi · 08-24-2007, 07:58 PM

I just checked all the settings and there is no such setting. It's a VIA MII motherboard, anyone know where I can find such a setting?

2k1Toaster · 08-24-2007, 11:49 PM

Via uses the Pheonix Award BIOS, so it looks like this:

You see the "Power Managment Setup"? Try there...

salvi · 08-25-2007, 02:42 PM

I was in the PowerManagement setup but didn't find the option.

2k1Toaster · 08-25-2007, 03:03 PM

Quote: Originally Posted by salvi

I was in the PowerManagement setup but didn't find the option.

"Restore on AC Power Loss". Change that. It really isnt that hard. Unless you bought a really old board, your BIOS should look like that. I have had the M10k which is older than the MII and mine had this option. This is a basic option that has been around forever. The only BIOS's I know of that dont have this option are either really really old (and then it was usually a user settable jumper on the mobo itself), or laptops (they have batteries, so they dont care).