Power Brick 12v 5a Big Enough? MoCoSo PC

**we87** · 05-17-2012, 07:33 PM

I have a pre-built PC from www.mo-co-so.com with a built in M2-ATX psu, and motherboard D945GCLF2.

I am trying to power it from my bench with a ac-dc adapter that is 12 volts at 5 amps. However, the PC clicks on for about two seconds and "tries" to post then the entire pc will shut down, restart, and the HDD led and POWER led just stay on and nothing else happens. Nothing appears on the monitor, and I cant hear the case fan spinning any longer. The M2-ATX is in P1 mode and works perfect in my car.

Am I not using enough power? This same power brick worked a few years ago to install windows on the pc, now that I am trying to change a few things I cant get it to power the same PC?

Any and all information is GREATLY appreciated. Thanks In Advance!

**dmcdlrn** · 05-17-2012, 07:49 PM

Not enough power me thinks. The m2-atx is either 140 or 160 (if you have the HV not likely) watts depending on which model you have. 5amp at 12v is 60 watts. Now, just because the m2-atx is 140~ watts doesn't mean it pulls it all the time. My guess is it starts pulling it during bios as usually CPUS go to 100% usage during POST and browns out which is VERY bad for the MB.

I would definitely look for a bigger power supply. I'm thinking you need about 12amps at 12v to be safe for the 140 watt m2-atx.

I differ to oldspark whom will definitely respond to this and set you and me straight

**cd36** · 05-17-2012, 08:21 PM

The HV one is the 140WATT the regular m2-atx is 160. And yes that power supply you have is only good for 60w. You are most likely severely underpowering your computer.

160/12=13.3 amps. Aim for 80% derating on your power supply to make sure you don't overwork it too.

13.3/.8=16.6

You should be looking for something that can deliver 17amps.

And yes I know they won't be maxing out their m2-atx but is rather have to much than not enough.

Sent from my HTC One X using Tapatalk 2

**we87** · 05-17-2012, 08:54 PM

OKay, thanks for the replies guys. Going to look for an alternative to power this carputer in the house....

What about laptop bricks? Anybody use those? I have a Universal one that I think is a 15volt, not sure on the amperage though. Wouldnt going higher in voltage mean I can have lower amperage?

**we87** · 05-17-2012, 09:49 PM

OKay, I ditched the entire power brick idea and went for the real ATX power supply solution, as found in the FAQ section.

I am using a 300watt ATX power supply, that according to the stick gives 15a on the 12v rail.

Using one of the HDD connections, getting 12v with my volt meter, hooked it up to my M2-ATX in "dumb" mode and the exact same thing happens. Powers on for a second, case fan and cpu fan come on, then the power light goes out, comes back on solid and the hdd light comes back on solid. Monitor never receives anything.

The M2-ATX still has working auto latch because in the recommended mode of P1 or whatever, if I take away the IGN and wait 60 seconds the M2-ATX shuts itself down. Could this be a sign of a working PSU but insufficient power? Or may I have friend the PSU trying to use the power bricks in the first place....

**we87** · 06-19-2012, 12:12 AM

The problem was the hard drive died. The actual power supply M2-ATX is just fine. Replaced the drive, everything is working properly again. And I am still using a atx power supply to give power to the M2-ATX.

Thanks again guys...

**OldSpark** · 06-20-2012, 01:47 AM

How dare dmcdlrn claim to differ from me! But if we do, then I'm wrong.

And sorry for my deferred (

) response - I've been getting the "blank screens of death" from mp3car - but we87 figured out the AC ATX PSU solution - usually the cheapest supply solution for high-current 12V & 5V etc supplies.