Mainboard accepting Fewer RAM Sticks

Discussion in 'Hardware' started by mokwit, Jun 12, 2008.

  1. mokwit


    The Problem.

    Reduced ability to accomodate memory - seems to be the number of GB rather than number of sticks but could be the number of full slots. Sympton is boot failure fixed by removing memory sticks.

    How it developed
    Had boot problems. Over a period of months it took 2 -3 rebooots, then 10 then 20 then infinity. Had 4x512MB installed. Solved problem first time by removing 1 512Mb RAM stick. Ran OK for a while with 3x512 then same problem again solved by removing another 512mb stick. Was working OK but 1G not enough and as there seemed to be damage on the gold contacts I bought 2x1GB thinking the RAM sticks were the problem and I could insert the 2x1GB to get total of 3GB. Didn't happen.

    Removed 1 of the two 512mb located side by side - now would not boot first time even though I had removed not added. Tried various combinations of 512mb and 1GB sticks and found that there seemed to be no one stick or no one slot that was identifiable as a problem. The board will accept 2x512mb or 1x1GB but not 2x 1GB which is the minimum I really need. Did not try 512mb + 1GB.

    Usually it got as far as mouse and keyboard lights before stalling (stalls before monitor backlight come on) before I removed the offending sticks. Now it gets this far with 2x1GB and then stalls before monitor backlight, but does NOT get this far with all slots full i.e 2x1GB and 2x512mb. boot hangs earlier it seems.

    Observations that may help someone to isolate the problem:

    Boot problem was not present with warm start ie. green restart button pressed unless I set CHKDSK in which I had the non boot problem.

    If during a power cut I kept the UPS on with PC switched off it would usually (but not infallibly) boot first time. If I switched off UPS there was always a problem rebooting and usually also a problem with Samsung monitors claiming they were not connected to PC. Had problems with a previous quad card not running all four monitors after a switch off. Have tried without UPS and it makes no difference so not UPS. Already tried a new Power Supply.

    I think this is some kind of dying mainboard/component problem - which means it is going to be hard to isolate/fix - but could it be something simple like bad earthing? The problem is linked to mainboard power off rather than PC power off it seems. As I understand it there is power flowing to the main board when PC is switched off.

    I think I have eliminated total memory+ total page file being over the (4GB?) limit as a possible cause but not entirely.

    Any suggestions?
  2. Sounds like you have too much draw for the circuit. You may need an electrician. See if it boots if you cut down on the various appliances you have plugged in. Take a voltmeter to the old line and see if it's low, under 110V or so.

    Or take the computer to a different circuit (or two different circuits) and see if it boots without accessories. Also, unplug all USB devices as they can sometimes interfere with booting if they're malfunctioning.

    As for RAM, you can't know if it's a RAM chip unless you swap out all of them. Muphy's law says that the failures can come in pairs.

    Probably electrical, though.
  3. Banjo


    start at the start, swap the power supply and see what happens.
  4. He wrote that he already swapped the Power Supply.
  5. Banjo


    So he did, my bad. It's a wierd one alright, anyway to read CPU temp, when they get too hot all sorts of screwy stuff happens. Does the cpu fan run properly, is the thermal paste/ tape intact?
  6. some ideas:

    I don't think there is any power other than the cmos battery (very low draw) being applied while computer is off.

    Did your new power supply have a higher wattage rating than the old one? Seems like if you need more power drive that would be a solution. Try a much higher wattage and (high end if possible) clean supply.

    Haven't looked at bios in a while, but there may be some diagnostics you can do if your mboard supplies them (checking regulated voltage/temps, etc...). If the temp is running way to high (some bios programs will show limits) you could try to cool it down more (open case put next to large fan) and see if that does anything to improve booting juice. When you said contacts were burned, sounds like arcing/heat issue. If it solves it, you can try to add/boost some internal fans.

    I'm doubting the house supply issue, but if you want to try, you can find a circuit breaker with the highest amp rating, disconnect everything on that line but the computer and see if it juices up any better.

    Another option, if you think you are power starved, is start up with minimal peripherals connected (i.e. disconnect cd drive, maybe even monitor temporarily on bootup). At least that might give a clue if it truly is juice starvation.

    type ram start in search bar and
    look under troubleshooting if mb does not start.
  7. Jaba122


    I'm not sure if this will help, but I had a similar problem a while ago, the box wouldn't boot, it would start counting the RAM very slowly, then hang. I removed/replaced every dang thing in this PC, RAM HDs, PSU... nothing helped. I almost bought a new mobo. You want to know what was the problem? A damn iPod connected to the USB port! :D ... weird...
  8. kinar


    I'd also second the recommendation to test the outlet on the wall.

    If you are familiar with using a multimeter, you can do it yourself. It's amazing what kind of wierd issues low or high power can cause.

    I had an issue a while back where I went through 3 Power supplies and a mainboard over the course of about 6 months before I decided to test the outlet and sure enough it was 3 volts high. Called the electric company about it, they adjusted it and never had a problem again.
  9. Not disputing your experience, but something about that sounds very bizarre. Was it 3V rms or DC offset?
    Should not be DC, as the house transformers are CT grounded at zero.

    Even if it was DC offset, it should not pass through the supply as transformers don't pass DC, at least one PS side is grounded at center (zero).

    If it is an RMS offset, the supply should filter that offset through it's internal regulators (haven't checked the input tolerance for regulators in a while, but 3V seems pretty small to cause damage).

    Also, a higher voltage would not be the cause of lack of supply power as again, the internal regulators regulate the output wattage and voltage regardless of the input voltage.

    One other thought I had, is if it is possible to control the RAM and CPU frequency through BIOS, you can also try to slow that down to reduce power draw. I've also read that some RAM cards require different dc supply voltages, you can check the RAM manufacturer and alter that through BIOS as well.

    Keep us posted on the results.
  10. mokwit


    Hi, thanks to all replies. Unfortunately I have pretty much gone through the above suggestions already.
    #10     Jun 14, 2008