Has anyone gotten a sproggy to work with EPIA boards? - Page 2

digitallexus · 02-22-2003, 08:14 PM

I bought an ATX extender cable and then cut it in half so I could put a meter in-line to measure the amount of current used on each rail.

Epia M9000
512MB PC2700 RAM
Microsoft Intellimouse Optical
Microsoft Elite Keyboard
Ethernet attached

(also attached during these tests, but not part of these current measurements):
IBM Travelstar 5400 40GB laptop HD
AOpen Slot load DVD

Measurements were made by placing a Fluke 189 digital meter in-line betwen a 250W ATX power supply and the motherboard. The meter was placed in "Fast-Max and hold" mode to measure peak instantaneous current usage.

The results:

12v:
Powerup: 185 mA
Max (playing DVD) 219 mA

5v:
Powerup: 2.939 A
Xp loading: 3.366 A
Playing DVD: 3.48 A
Max: 3.965 A

3.3v:
This is where it gets a little more interesting.
Tying all 3.3v ATX lines together with the meter in-line prevents the motherboard from posting. There is a peak 7.673A on initial powerup, but no POST. I verified the motherboard could post with all lines tied together, but with no meter inline.

Next I tried only measuring ATX pin 1 & 2 (3.3v) together, while keeping pin 11 (3.3 + 3.3 v sense) separate

The motherboard posts in this configuration and measurements are:

pin 1 & 2: startup: 1.85A
pin 11 : startup: 1.27A
-------------------------------------------
3.12A

Now, adding these up doesn't equal the 7.673A I saw in the failure case (with all 3 lines tied together). I am not really sure what this means. My electronics theory is pretty marginal. I don't know if this is just an artifact of the measurement process. Maybe while measuring one set of pins, more power is being sent down the others path since it has less resistance?

My only conclusion is that it must need upwards up 8A peak on startup. ??

I also measured the 5v standby line to see how much power is used while the computer is under standby mode:
176 mA while the computer is on
297 mA while windows is in standby mode

note: with the computer is plugged into an ethernet hub, power usage in standby drops by 30mA, apparently stealing a little power from the hub?

So for a 24 hour period you would need 7.2 A-hours of battery life. I suspect this might be much less with slower RAM, and less than 512MB! In any case, it was quite cool to put the computer into standby while streaming music over the internet, then resume a minute later and have the music instantly startup where it left off and continue streaming. nice.

digitallexus · 02-22-2003, 10:53 PM

Alright, after measuring the M9000 power requirements and finding the possible extreme requirements for the 3.3v rail, it was time to build something new to try.

Tonight I worked up a Sproggy 2.7x

The 2.7x is has two Max 787's and two Max 788's.

This should provide the following power output:

3.3V: 10A (13A peak)
5V: 10A (13A peak)
12V: 1.3A

Luckily I had lots of extra sproggy components, so I had everything necessary to double the 3.3V output current.

Okay, now the bad news. I built it, powered it up, and same result. Motherboard fan powers up, but it never POSTs.

Since I don't have the 2.8, I don't have the ATX power-on signal integrated. This worries me that the motherboard is not expecting power, or is not providing the correct behaviour on ths PS-ON pin.

Not sure what else to try at this point.

digitallexus · 02-23-2003, 08:19 PM

I modified my 2.7x today and added 5v standby and a transistor to support the PS-ON pin 14 ATX signal.

After initially applying power (i.e. only 5v stdby), I see the network light on the motherboard establish connection with my ethernet switch, so 5v standby power is good.

Next I short pins 6 and 8 on the motherboard to power things up. The sproggy powers up just fine in response to this action.

No go though. same old story. processor fan spins up, but no POST.

????

digitallexus · 03-02-2003, 06:34 PM

More experimenting...

Using a known good desktop ATX power supply hooked up to the M9000...

The Power good line seems to be unncessary. Everything powers up just fine with this line "cut"

Next I tried removing the PS_ON line and starting the power supply by shorting to ground. (i.e. the motherboard is not connected to the power supply's PS_ON). The results are very interesting. The power supply starts and provides the necessary voltages. The M9000 fan starts but does not POST. Exact same behaviour as the sproggy! Could be a coincidence, but this reinforces my original theory that its not a lack of power (especially since I have modified my 3.3 rail) but rather a signalling problem with powergood or PS_ON.

PTCruiser · 03-03-2003, 10:02 AM

Many thanks for all your work...

I have a M9000 and I'am building my dc-dc supply now with a "new" design...

Basicly I use a PIC for the shutdown ctrl and the PG, PS_ON...

Removed all the negative voltage...

Your thread is very very helpfull...

I'll have a problem with my 3.3V

3.3V @ 7.673A on startup that's hudge....

On Via Spec:
Playing DVD
+3.3V 3.37V 3.38A 11.3906W

Perhaps a big caps on the 3.3V will be enough for the startup...

Hope you'll find the bug with powergood or PS_ON signal!

If I find something I'll let you know...

What is the specification for the PS_ON signal? Did you check it?

Quote:

PS_ON# is an active low signal that turns on all of the main power rails including 3.3VDC, 5VDC,
-5VDC, 12VDC, and -12VDC power rails. When this signal is held high by the PC board or left open
circuited, outputs of the power rails should not deliver current and should be held at a zero potential with
respect to ground. Power should be delivered to the rails only if the PS_ON# signal is held at ground
potential. This signal should be held at +5VDC by a pullup resistor internal to the power supply.

PTCruiser · 03-03-2003, 03:07 PM

I forgot to tell yo that a couple of member of the french forum have Epia-800 & Sproggy working....

The problem seems to be with the m serie...

mp3xe · 03-12-2003, 09:29 AM

Bump.
I tried my Epia-M with a Sproggy 2.8+ this weekend.
Powers up for about 5sec. then shuts down. I see the processor fan running and hear the hd spin up.
Darn, I had hope because no one had posted thier experiences with the 2.8+.
This stuff is over my head so I'm hoping someone else solves this problem so I don't have to go with a different PS.
Robert

PTCruiser · 03-12-2003, 09:47 AM

I'm building a dc-dc (modified version based on the sproogy)

mp3xe what kind of EPIA did you have...

Several member of www.divx-car.com have an Epia 800 & sproogy working (not yet a M9000 % sproogy)

I already heard the similar proroblem...

he put a bigger cap on the 5V output (replace the 470uF by a 1000uF) and the problem was solved...

Topic in french:
http://www.divx-car.com/phpBB_Fr/vie...=asc&start=120

I'm on this thing....hope my M9000 will boot soon!

mp3xe · 03-12-2003, 11:54 AM

I have the m9000 also.
I'll keep an eye out for you new design.
Thanks,
Robert

Scafremon · 03-13-2003, 12:41 AM

Quote:

Originally posted by CrazyLittle

HOWEVER - you'll find that it's much easier and cheaper to probably just daisy-chain two of the mini-ITX power supplies together (one for the mobo components, and one for your additional hardware).

i just recently ordered a m9000, and have been trying to figure out the best power supply for my board and components. My goal is to try and provide power for (2) DVD drives, along with a 3.5" hard drive. From what I've learned on this forum, this appears to be a tad much for one of the common 60w DC power supplies.

Could it really be as simple as using (2) of these mini-itx power supplies?

Thanks for everyones help.

I think I've logged a good 3-4 hours reading this forum, and I will now go back to more reading.

digitallexus · 03-13-2003, 06:07 PM

Since you have all of the hardware you want to run, I would hook the m9000 up to a full sized desktop power supply and measure your current.

You'll need an ATX extender cable (unless you want to cut up your power supply cable).

For each voltage rail (5v, 3.3v, 12v, etc), place a meter in series.
Power up the board and perform various tasks. Watch for the max amps used.

You can then compare against the specs of available power supply. They usually list the max current (Amps) that can be drawn without overloading the power supply.

You can also manually calculate power requirements for devices by looking at the label. They usually will list power needed for each voltage.

You can always convert to watts and then add them all together, but that is only a generalization.

slboytoy · 05-10-2004, 06:33 PM

So has anyone found an answer yet??

All I did was using a MK 3.5 and Jeff's SDC, I just hooked up the +12 for the motherboard to the relay on the SDC. I'm going to put it through a 7812, but as it looks now, it boots up fine.

No PG
No -5
No PS-ON