Thread: M2-ATX(-HV) 160 watt Intelligent DC-DC PSU

Well, I was the one that brought up this RFI business. turns out the PSU is likely not the cause of my RFI.

I pulled my vehicle into the garage and plugged in an AC power supply to the wall and the interference still existed.

I get AM and AM HD great though!

FM still sucks. Considering I'm running an older motherboard with a P4, perhaps a newer generation of technology will help.

The current case is steel. http://www.newegg.com/Product/Produc...82E16811154062
There is a vent in the top. Maybe that's letting the RFI 'bleed' through.



This is in an Explorer. Computer is in the back. The radio is under the back seat.

@joshuo. I heard that some people like the OPUS better. I was going to go down that road until I had the same results with an AC PSU.

Originally Posted by peterfnet

There is a vent in the top. Maybe that's letting the RFI 'bleed' through.

I don't think it would. It should still act like a cage of Faraday. S mesh is fine as long as it is grounded as well. (unless it has a rubber gasket sealing it from the box, i don't see why it would give you issues.

Originally Posted by Virac

Im having a few problems with my M2-ATX.

1. When i turn off my car the power pulses and the computer does a hard restart, then 5 secs later will shut down, I have the jumper in position 1. I have tried swapping the IGN and POW lines but I know that is not the issues cause when i turn off the car the computer powers off instantly and when it comes back on i get a warning that the system didn't shutdown properly.

I'm having the same issue - when I turn the ignition off, there seems to be some kind of a power pulse, the computer simply powers off without proper shutdown, though the monitor stays on (or maybe it just turns back on right away). In 5 seconds everything turns off.

Originally Posted by Virac

Update: Finnally got a 13.8V AC/DC power supply and the M2 behaves properly. For other reason main power must be fluctuating.

So it wasn't enough voltage? Could it be the case for me too?

Originally Posted by alpax

I'm having the same issue - when I turn the ignition off, there seems to be some kind of a power pulse, the computer simply powers off without proper shutdown, though the monitor stays on (or maybe it just turns back on right away). In 5 seconds everything turns off.

Just wanted to share my experience. I had this problem, tried to replace the PSU - no change, the new one behaved the same way. I did some more experiments and finally could make it work as it should!
I just used the power filter, which came with Lilliput: connected the ignition through that filter, and it solved the problem! Now it works as it should.

yes, i can also confirm that if your batt+ is hooked to a power source that fluctuates when you turn the REM lead off- the m2 will shut off completely for a split second and then resume normal shutdown pulse.

its not really a fault with the m2 though. you must have the batt+ of the m2 powered with a steady 12v at least even when shutting the ignition off (this fluctuation can happen on more circuits then you would think) so if its happening its really an install problem.

ludikris, im guessing that power filter has capacitors in it, thats why its working for you. im sure any decent sized cap across the batt+ and batt- of the m2 would help in those situations.

Originally Posted by trader007

its not really a fault with the m2 though. you must have the batt+ of the m2 powered with a steady 12v at least even when shutting the ignition off (this fluctuation can happen on more circuits then you would think) so if its happening its really an install problem.

Hmm... I thought the whole idea of this PSU was to receive unregulated input, which could fluctuate from 6 to 24V, and output steady 12V, 5V, and 3.3V.
If it cannot handle this, I believe it's definitely a design flaw.

BTW, in my case the power from the battery+ is pretty steady - I double-checked that.

It does not need to be regulated 12v, it can be anything. It can survive down to 6 or 7 I think when cranking. It works just fine on mine.


I think what he is saying (although I have never experienced this to be true) is anything between 12v and charging voltage is ok when shutting down, lower and it doesnt?

On mine though I can do whatever and it works. I can turn on the HID lighting which draws an ENORMOUS current from the battery fast with the car off and the CarPC in its 30s before shutoff, and the PC will keep on truckin'. I can start the car when the CarPC is in its 30s before shutoff which definately dips it to 6 or 7 and it will keep working just fine.

Only difference is I have the regular M2, not the M2-HV. Also I have a real M2. If you bought it off of ebay for $30 to $50 then you have a chinese knockoff copy that has known problems. Lots of problems. You get what you pay for. Expect $70 to $90 new.

Originally Posted by 2k1Toaster

It does not need to be regulated 12v, it can be anything. It can survive down to 6 or 7 I think when cranking. It works just fine on mine.

Yes - that's how it's supposed to be. In my case any disconnection of the ignition line - when I was turning the key to OFF or starting the engine - caused some impulse from the PSU, which instantly powered off my computer without shutting the OS down, and eventually it died so could not boot up. My fix with adding a filter on the ignition line made it work as it should. Now I can start the engine with the computer running, can turn the ignition off, then back on - it's working. Only after 5s delay (I use P1 mode) it starts shutting down.

Originally Posted by 2k1Toaster

Only difference is I have the regular M2, not the M2-HV. Also I have a real M2.

Mine is the regular M2 as well, and it seems to be real - I bought it for ~$75 from mo-co-so.com.

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