Announcement

Collapse
No announcement yet.

HP (Asus) M2N68-LA only boots sometimes

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    HP (Asus) M2N68-LA only boots sometimes

    Hello, everyone, I've got an HP Pavilion a6530f computer that got drizzled on, with a problematic Asus M2N68-LA motherboard. First, the backstory:

    After the computer was rescued from the weather, I kept trying to power it up to no avail. (That wasn't a good idea, I should have cleaned it first. Lesson learned.) Eventually, I ripped the board out of the PC and cleaned the absolute heck out of it, back and front, and even under the chipset heatsink. After inserting another CPU, I finally got the board to boot, which was an amazing sight. That was in August of 2015. After doing the cleanup and CPU procedure, the computer always seemed to work mighty fine.

    Today, however, when I turn on the computer, most of the time, it does boot up. However, it sometimes doesn't boot up, just sitting there with the fans spinning, but no monitor signal at all. I investigated the motherboard, and oh nooooooo, there's KZGs everywhere! I know very well from reading here that they can fail without visual indication. Here's the list of them:
    • Amount - uF ----- Voltage Diameter Ripple --- ESR
    • - 11x-----820uF - 6.3V -- 8mm -- (1140mA 36mΩ)
    • - 6x-------1000uF 16V --- 8mm -- (1870mA 21mΩ)
    • - 8x-------1500uF 6.3V -- 8mm -- (? --------- ?)
    • - 1x-------470uF - 16V --- 8mm -- (1140mA 36mΩ)


    I've picked Nichicon/Panasonic replacements for these caps. One issue, though, is that I can't find the ripple nor ESR for the 8mm variant 1500uF 6.3V KZGs on this KZG datasheet, there's only ripple/ESR for the 10mm variant. My board's caps are definitely 8mm. I just went ahead and picked the Panasonic EEU-FM0J152 (1500uF, 6.3V, 2.18A and 19mΩ) to replace them.

    The question is, what is causing this issue? Could it be the caps, or did the weather somehow manage to damage this poor board just enough so that it only boots most of the time? Any ideas?

    Thanks in advance!

    #2
    Re: HP (Asus) M2N68-LA only boots sometimes

    could be the power supply. seeing that its an oem computer, the psu is prolly full of bad caps too. a bad psu will kill a motherboard after some time of use. tear open the psu and post it in the power supply subforum.

    Comment


      #3
      Re: HP (Asus) M2N68-LA only boots sometimes

      Originally posted by ChaosLegionnaire View Post
      could be the power supply. seeing that its an oem computer, the psu is prolly full of bad caps too. a bad psu will kill a motherboard after some time of use. tear open the psu and post it in the power supply subforum.
      Thank you for your response. I have just opened the power supply to check it and all of the caps look great. For the record, the power supply is a Delta DPS-300AB-19 A. Running the motherboard on another power supply still results in the same behavior.
      Last edited by racecar56; 02-14-2017, 08:54 PM.

      Comment


        #4
        Re: HP (Asus) M2N68-LA only boots sometimes

        Usually when I got a computer from scrap, first thing I would do is inspect the dust, if the dust seems like it got water on it, or once it dried up (and looks cemented), all those stuff will went to the wash tub with no questions ask.

        Comment


          #5
          Re: HP (Asus) M2N68-LA only boots sometimes

          Not sure if this model is one of the problem ones, but there were some that had the bad solder bump issue that was common with many nVidia chipsets of a certain age. Basically, the solder bumps on the main chip would crack over time due to thermal stress and cycling. Various heat treatments could temporarily fix the problem, but ultimately, you might be better off with a different motherboard.

          Comment


            #6
            Re: HP (Asus) M2N68-LA only boots sometimes

            Originally posted by CityZen View Post
            Not sure if this model is one of the problem ones, but there were some that had the bad solder bump issue that was common with many nVidia chipsets of a certain age. Basically, the solder bumps on the main chip would crack over time due to thermal stress and cycling. Various heat treatments could temporarily fix the problem, but ultimately, you might be better off with a different motherboard.
            This board indeed has a nVidia chipset, and I experienced the nVidia solder problem for myself on one of my laptops seven years ago (dv9000 w/dedicated graphics), so I do know about that issue. Maybe I should try heating up the nVidia chipset on this board.

            I think that I'm going to have to buy an ESR meter, test some of the KZGs from the board, and see if any of them are bad. If the caps are good, the board gets recycled, and if the caps are bad, then the caps get replaced, hopefully resulting in the board being fixed. I could most certainly use an ESR meter, not only for this but for other projects as well.

            Would anybody like to recommend a particular ESR meter for me to get? I want something that's cheap, if at all possible, without making it a bad product.
            Last edited by racecar56; 02-18-2017, 08:25 PM.

            Comment


              #7
              Re: HP (Asus) M2N68-LA only boots sometimes

              Well, I purchased an ESR meter, that being a "12864 Mega328" one from Frentaly of eBay. According to it, several, at the very least, of the board's KZG capacitors have not failed as of yet. That suggests that it's probably the chipset to blame.

              Going with that, I heated up the chipset, and so far, I've not had any further no-bootup problems, however, I doubt the likelihood of this lasting, due to the nature of the issue. It's probably best to simply recycle the motherboard, especially since I have already replaced it with another one in the computer that it came from.

              It's definitely a good thing that I bought that ESR meter, it has been useful and I know that it will continue to be. I highly recommend that ESR meter for any capacitor tinkerer such as myself. It's definitely a wise investment.

              Edit: Scratch that, the board failed to boot, I tried to heat the chipset up once more, and then the board totally died (won't turn on).
              Last edited by racecar56; 03-14-2017, 07:15 PM. Reason: The board died.

              Comment


                #8
                Re: HP (Asus) M2N68-LA only boots sometimes

                Sometimes if the board is bent (bad heatsink retention system or crappy pc case), the cpu socket and bga chips can fail due to cracked solder joints.

                Comment

                Working...
                X