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Is the M4-ATX under powered for my setup?

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  • Is the M4-ATX under powered for my setup?

    Hi,
    I have just installed my carpc in the jeep but am having what I think is an under powered system issue.

    carpc: - Zotac mini itx 9300 with intel duo 2gig processor
    - 4 gig ram
    - and I am also powering my Lilly 699 from the m4 as well.
    - The usual peripherals. usb gps receiver, Dab radio

    Situation: when system is on, I get a slight flicker on screen. The flicker is not at a constant rate and is NOT engine rev dependant. This flicker continues even in reverse can mode on screen.

    Does this sound like the M4 is infact under powering my carpc? The M4's description clearly states that it can power a dual core processor.

    thanks

  • #2
    it kind of sounds like a ground loop issue.

    if it couldn't power the setup, then i think you would be having a different set of problems--like turning off randomly, or devices not staying on when the psu is on..
    My OLD 2001 Mitsubishi Eclipse GT:
    "The Project That Never Ended, until it did"


    next project? subaru brz
    carpc undecided

    Comment


    • #3
      That load wouldn’t even make the M4 raise a sweat.

      Agree with soundman, ground/shielding problem or noise from the M4, if you haven’t tried a filter between the M4 and the LCD supply then that would be a place to start.
      Palm sized ainol MiniPC, 8" Transreflective PRO, Win10, Reverse camera, Dual 10HZ GPS RX's for Speed Display & Sat Nav, FM-DAB & Phone Modules, iDrive interface. T-Screen HVAC control, custom microcontrollers, microcode and FE.

      Comment


      • #4
        Thanks for reply guys. I have earthed my amp and carpc at the same location as what jeep has used to earth car's electrics. I would have thought this location would have been ideal.

        Should I create a new earth point?

        Also, any suggestions on filter type/rating etc? And if that doesn't work, I guess o need to start reading up on solving ground loop issues :-/

        Comment


        • #5
          Actually now that I think about it, when I bench tested my pc and m4, I noticed the same flicker. I just assumed there was an issue with my bench power supply. So I guess we have eliminated groundloop and are left with either shielding issue or m4 noise.

          If it is a shielding issue, how would I best tackle this?

          If m4 noise, do I have any chance of ratifying without having to send back? Would a filter help to solve this?

          Comment


          • #6
            The Vehicle earth points and what appear to be big beefy cable and ground bolts are all fine at DC (the vehicle battery) and possibly helpful at low audio frequencies but are pretty much meaningless as the noise/interference components rise into RF frequencies and these are the sort of signals that emit from switch mode power supplies and PC systems.

            I believe that a number of LCD’s come with a filter built into the lead, but I’m sure they are available, so hopefully someone can point you in the right direction.

            If the noise was apparent on the bench there’s a good chance that the noise is coming in via the supply leads. However there is also an injection path across the video cable by virtue of the PC- to PSU earth and the Monitor to PSU earth point. The M4 has some substantial noise on its +12v output lead so this is the likely cause.

            You could try powering the screen with a small battery for a quick test. Only disconnect the +12v lead to the monitor from the PSU +12v Pin, leave the monitor earth connected, all you are trying to do is to quickly eliminate the +12v pin itself. This will give you a good idea if a filter is going to solve the problem. Like everything in the CAR-PC world, some monitor-MB combination just don’t have this problem, others do.
            Palm sized ainol MiniPC, 8" Transreflective PRO, Win10, Reverse camera, Dual 10HZ GPS RX's for Speed Display & Sat Nav, FM-DAB & Phone Modules, iDrive interface. T-Screen HVAC control, custom microcontrollers, microcode and FE.

            Comment


            • #7
              Originally posted by Mickz View Post
              The Vehicle earth points and what appear to be big beefy cable and ground bolts are all fine at DC (the vehicle battery) and possibly helpful at low audio frequencies but are pretty much meaningless as the noise/interference components rise into RF frequencies and these are the sort of signals that emit from switch mode power supplies and PC systems.

              I believe that a number of LCD’s come with a filter built into the lead, but I’m sure they are available, so hopefully someone can point you in the right direction.

              If the noise was apparent on the bench there’s a good chance that the noise is coming in via the supply leads. However there is also an injection path across the video cable by virtue of the PC- to PSU earth and the Monitor to PSU earth point. The M4 has some substantial noise on its +12v output lead so this is the likely cause.

              You could try powering the screen with a small battery for a quick test. Only disconnect the +12v lead to the monitor from the PSU +12v Pin, leave the monitor earth connected, all you are trying to do is to quickly eliminate the +12v pin itself. This will give you a good idea if a filter is going to solve the problem. Like everything in the CAR-PC world, some monitor-MB combination just don’t have this problem, others do.
              Thanks for the tip Mick. I will do some testing this weekend and report. I have also seen your work log and must say, your testing is extensive. I was especially interested in the cage you made for the M4. any chance of a how-to on this? I will try powering the LCD from car with egg filter that came with the Lilly. Then try your M4 cage. all else fails, I might have to invest in a new PSU?

              Cheers
              mos

              Comment


              • #8
                Originally posted by Mickz View Post
                The Vehicle earth points and what appear to be big beefy cable and ground bolts are all fine at DC (the vehicle battery) and possibly helpful at low audio frequencies but are pretty much meaningless as the noise/interference components rise into RF frequencies and these are the sort of signals that emit from switch mode power supplies and PC systems.

                I believe that a number of LCDís come with a filter built into the lead, but Iím sure they are available, so hopefully someone can point you in the right direction.

                If the noise was apparent on the bench thereís a good chance that the noise is coming in via the supply leads. However there is also an injection path across the video cable by virtue of the PC- to PSU earth and the Monitor to PSU earth point. The M4 has some substantial noise on its +12v output lead so this is the likely cause.

                You could try powering the screen with a small battery for a quick test. Only disconnect the +12v lead to the monitor from the PSU +12v Pin, leave the monitor earth connected, all you are trying to do is to quickly eliminate the +12v pin itself. This will give you a good idea if a filter is going to solve the problem. Like everything in the CAR-PC world, some monitor-MB combination just donít have this problem, others do.

                I agree with Mickz on this one. I have an M4ATX running a Zotac H55 with a 2.9Ghz i7, 8GB of ram and a HD 5570 video card, all with no problem (including a few light usb add-ons as well).
                I would:
                • Try hooking the monitor up to a different 12v source
                • Remove all of the other usb connections
                The filter that Mickz mentioned on the power lead is a "ferrite bead". They're usually molded into a cable but you can buy them separate from companies like Digi-Key or Mouser Electronics (there are tons of others as well).
                You may also want to try a different video input cable and possibly a different source (if you're using the VGA, try the DVI or the HDMI. I had that same 9300 board with a 65w q9550 and a 669GL using the HDMI out. I had the 669 powered off of a DCDC-USB with no flicker and the M4 had plenty of power for the ridiculous amount of USB devices I was throwing at it.
                I'm definitely inclined to think that it's not your M4 (but then again, if there is any ripple on the output it's not impossible).
                You could also use a multi-meter (volt meter) to test it. Hook up to the 12v positive and the negative (ground/earth) and in DC mode, it should read 12v (obvious, I know). Then switch it to AC mode. It should read all 0's. If it bounces around, there is some ripple on the output which would indicate a poorly filtered DC output in which case you would want to look for a different source for your monitor power (and probably a whole new Pwr. Supp if there's much ripple at all).

                Comment


                • #9
                  I doubt the RF shield (cage) will make any difference to LCD interference because of the frequencies involved.

                  I was forced to come up with that idea in a last-ditch attempt to overcome Digital radio and GPS signal desensing caused by the M4 - it did!

                  The monitor I use has no interference with 15 feet of VGA and reversing camera video feed bundled with power and USB cables over that distance. But as posted above, any of these things can cause a problem in some systems.

                  If the signal clears up with a separate +12v line and if a standard filter has no effect then I can show you a simple two component filter to try which may solve the problem.
                  Last edited by Mickz; 10-25-2011, 05:42 PM.
                  Palm sized ainol MiniPC, 8" Transreflective PRO, Win10, Reverse camera, Dual 10HZ GPS RX's for Speed Display & Sat Nav, FM-DAB & Phone Modules, iDrive interface. T-Screen HVAC control, custom microcontrollers, microcode and FE.

                  Comment


                  • #10
                    I will start with powering LCD via separate +12v and check result. If I get the same flicker effect, I guess its time for a new psu. Changing the LCD signal line is not really an option as my Lilly does not have hdmi or dvi out and really don't want lay another cable yet as I just put the car together. My wife will rip out the kitchen knifses.

                    I will try all suggestions.made in the next few days - thank you both for your suggestions.

                    I just remembered - when bench testing, I was actually powering LCD from supplied wall power supply and not the m4. I guess this means my m4 is faulty?

                    Comment


                    • #11
                      If the M4- powers the PC then IMHO it's unlikely to be faulty. Lot of people complain about this with various systems and supplies.
                      Palm sized ainol MiniPC, 8" Transreflective PRO, Win10, Reverse camera, Dual 10HZ GPS RX's for Speed Display & Sat Nav, FM-DAB & Phone Modules, iDrive interface. T-Screen HVAC control, custom microcontrollers, microcode and FE.

                      Comment


                      • #12
                        Originally posted by mos33y View Post
                        I will start with powering LCD via separate +12v and check result. If I get the same flicker effect, I guess its time for a new psu. Changing the LCD signal line is not really an option as my Lilly does not have hdmi or dvi out and really don't want lay another cable yet as I just put the car together. My wife will rip out the kitchen knifses.

                        I will try all suggestions.made in the next few days - thank you both for your suggestions.

                        I just remembered - when bench testing, I was actually powering LCD from supplied wall power supply and not the m4. I guess this means my m4 is faulty?

                        Yeah, I only thought that input-switching halfway through. Sorry about that (I had my 669 on HDMI but I have adapters on the PC side so I was converting DVI to HDMI at first before I got the long HDMI/USB cable). Besides, if it's flickering with the B.U. Cam input too (which I also managed to pass over) then it wouldn't be a MOBO video out issue.
                        If it was fine with the Wall Supply and not fine with the M4, that would imply that "the M4 is bad" but if it runs your pc, it may just be that the Lilly doesn't like the output ripple from the M4 (presuming that there is some ripple).

                        Comment


                        • #13
                          Originally posted by Mickz View Post
                          If the M4- powers the PC then IMHO it's unlikely to be faulty. Lot of people complain about this with various systems and supplies.
                          I hope so. Let's see if the weekend testing will yield some results.
                          Mos

                          Comment


                          • #14
                            Originally posted by shizzlehappens View Post
                            Yeah, I only thought that input-switching halfway through. Sorry about that (I had my 669 on HDMI but I have adapters on the PC side so I was converting DVI to HDMI at first before I got the long HDMI/USB cable). Besides, if it's flickering with the B.U. Cam input too (which I also managed to pass over) then it wouldn't be a MOBO video out issue.
                            If it was fine with the Wall Supply and not fine with the M4, that would imply that "the M4 is bad" but if it runs your pc, it may just be that the Lilly doesn't like the output ripple from the M4 (presuming that there is some ripple).

                            Comment


                            • #15
                              Originally posted by shizzlehappens View Post
                              Yeah, I only thought that input-switching halfway through. Sorry about that (I had my 669 on HDMI but I have adapters on the PC side so I was converting DVI to HDMI at first before I got the long HDMI/USB cable). Besides, if it's flickering with the B.U. Cam input too (which I also managed to pass over) then it wouldn't be a MOBO video out issue.
                              If it was fine with the Wall Supply and not fine with the M4, that would imply that "the M4 is bad" but if it runs your pc, it may just be that the Lilly doesn't like the output ripple from the M4 (presuming that there is some ripple).
                              No dont appologize, I appreciate any input.

                              What is baffling me though is: on bench test I was powering LCD with wall charger and I was getting flicker (using m4 to power the pc). I then used my home pc's 24pin mobo power supply and plugged into the zotec and I had no flicker on the LCD.

                              I guess this is why I keep on thinking that it is the m4 that is causing issues. Mine you the bench testing I had done was months ago and hence why my recollection is scetchy. This weekend will be moment of reconning. will definatly post results.

                              thanks guys

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