going from cheap enhance to pico-psu120

PSUs: The source of DC power for all components in the PC & often a big noise source.

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Ant6n
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going from cheap enhance to pico-psu120

Post by Ant6n » Mon Jun 18, 2007 11:21 pm

Hi,
I have a cheap enhance power supply on my athlon mobile 2800+/geforce 7600gs system, rated
3.3v - 7A
5.0v - 12A
12v - 5A
-12v - 0.3A
5vsb - 0.8A

I try to replace that with a picopsu120. I have a Dell brick rated 12.5A @ 12v. the pico psu is rated
5v - 8A
3.3V - 6A
12V - 7A
-12V - 0.05A
5vsb - 1.5A

My system seems to be running fine on the enhance psu (screen flickers once in a while, could be tvout). when i try the picu, the pc boots, and it runs in safe mode, but just before getting to the blue normal windows logon screen the computer shuts down. Once it actually got to the normal windows, but shut down when starting some 3d game. Does anybody have an idea whats going on?
One odd thing I noticed is that when turning on the computer, the voltage supply at the picopsu plug jumps from 12.1 to 10.5~11.1 volts. The cable from brock to psu is pretty long, and about 120 cm of it is pretty thin cable (not much thicker than audio cable), could this cause the problem?
anton

mcoleg
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Post by mcoleg » Tue Jun 19, 2007 12:09 am

how's the 5v rail? those cpus and boards use it as a primary power source, i think.

Bluefront
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Post by Bluefront » Tue Jun 19, 2007 1:46 am

It almost sounds like the current draw from the computer, exceeds the capacity of your power supply. My latest PICO 120W system acts very similar when I tried to run off a 5A power supply. That voltage drop to less than 11V is significant. The other things to check.....the cable wires may be too small in diameter {guage}. To carry sufficient current, you need big enough wires. And.....the stock PICO connector is ok for 5A. But for more current, it might be a problem. The 5V and 3.3V rails on my system remain very stable, even when the 12V line goes up/down.

I also run off a 12V battery.....my P4 system stays running down to 11.4V, maybe lower {haven't tried anything lower}. What is the rated current draw from your video card? That may be a problem. Try running the system off the built-in graphic card. Remove the one you're using....The PICO is a nice setup, but does have limitations.

Ant6n
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Post by Ant6n » Tue Jun 19, 2007 6:12 am

Thanks for the tip.
I read online somewhere the 7600gs draws up to ~30W (that's why i got it), but i can't really test it. Odd thing is that the previous power supply is rated lower on 12v than the pico, and i thought pci express draws mostly 12v (i might be wrong).
I tried running the hdd and the 4pin extra 12v supply of the motherboard with the old psu, and only running the mobo itself with the picu, but that shut me down on me, too.

Bluefront
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Post by Bluefront » Tue Jun 19, 2007 3:50 pm

Humm....I'm using a P4-2.4 on an intel board, with a laptop drive and a laptop optical drive. The video is an ATI 9250, with a TV Wonder pci card, a pci modem, and an extra USB card. That measures about a 50W draw at an idle, and about 110W draw running wide open. When not on the battery, I use a RadioShack 180W power supply. I haven't really had any problems with this PICO setup. Lucky me....I guess. :D

prodeous
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Post by prodeous » Tue Jun 19, 2007 10:37 pm

Did the standard kit, PSU without the ac-dc brick, come with additional cables like atx 12v 4 pin plug? Or is that extra?

I live in poland, and just recieved 4 nice picopsus, but only they picopsus without any additonal cables. And board won't boot without the additonal atx 12v 4 pin.

Bluefront
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Post by Bluefront » Wed Jun 20, 2007 2:10 am

The 4-pin MB cable is an extra. The std PICO comes with an attached cable with two molex, and one floppy power plug.

prodeous
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Post by prodeous » Thu Jun 21, 2007 4:12 am

Ok, thanks.

So now i have to find the P412v power addaptor. Wonder if the PCIe would work..

Either way, back on to the subject.

Ant6n
What happens when you remove the 7600gs, i'm guessing you don't have any older, much older pci card you can test with?

as with regards to the P4s you have. what type and speeds?

There is some information here on scpr about system requirements on power lines. not sure where it is, using that you can be sure if your PSU has enough power or not.

Ant6n
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Post by Ant6n » Thu Jun 21, 2007 8:38 am

p4 extra power is 4 pins, pcie is 6 pins. 4pin-molex adapters are actually pretty cheap. or you can build one yourself.
...as far as gfx, well, i dunno have a monitor, just tv :P

prodeous
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Post by prodeous » Thu Jun 21, 2007 10:00 pm

I tried to experiment.

For my project, phase one was 75% successfull.

I used a regular PSU, from one of the 12V i connected the PicoPSU. The P412v was dirrectly form the PSU. ANd system worked. When i shut down the system, only picoPSU turned off, main system was still a go :) (one step closer to cluster in a box ;))

Now i tried a second test. My other PSU in main system had PCIe 6 pin. So when both systems were off i just tried to see if it physicaly would work. And the PCIe 6 pin worked, with two pins sticking out. One issue was that the 12V was reversed, 12 where there should be ground and vice versa. Luckly that won't be hard to fix.

As for getting the 4pin molex adapter. I was hoping i could find it, but as more and more PSUs have them build in, its hard to find at local computer shops here in Wroclaw, Poland. (if anyone knows were i can find them, please tell me - thanks)

Now i just need a 9v battery for my volt meter and i'll check the amp read to see how much the sucker will suck :P

I expect that just the CPU/MB/MEM will be in the 50-70W range (maybe even less) What i need to find is a matx board that has voltage adjustable that is smaller then 24,4cm x 22cm for amd platform.

Either way. thanks for the info. (i'll get a pcie calbe and convert it at least for the first node.)

Ant6n
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Post by Ant6n » Sun Sep 02, 2007 11:41 am

followup on an old post:
after some sitting around, i went back to my project (athlon-m,2.5"drive,512mb,geforce 7600gs) - running a medium class graphics card on a picospu in a near silent htpc.

This time I got myself a monitor and a wattmeter. It turns out that with the 7600gs installed my system draws up to 125 Watt (with HL2), without it only 92 Watts. This is with the cheap PSU.
When using the picopsu and the onboard graphics, I can't get the system to draw more than 70 Watts. Thus I believe with the geforce and the picopsu I should have no more than ~105 Watts, which should be within the 120 Watts the picospu is suppossed to support.
But: when I start my system with the geforce and picospu, it shuts down some time during boot. It does so when it's actually drawing less than 70 Watts, which the system could withstand without the geforce installed.
Might that be because the system is using too much power on one of the rails?
Is there anything I could do (i.e. hookup another external supply), or should I try the pw200m?
thx

anton

ntavlas
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Post by ntavlas » Sun Sep 02, 2007 12:30 pm

I think that for a brief moment during start up a specific line draws more current that the pico can provide. A 200watt version should give you some more headroom, I always found the 120watt pico too limiting for a system with discreet graphics.

ddrueding1
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Post by ddrueding1 » Sun Sep 02, 2007 2:42 pm

I would do some more research on consumption on the 5V rail. It looks like the PicoPSU is a bit light on this rail, and it wouldn't show up as much on the watt meter.

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