m2a-vm weird post problem

Custom / CUSTOM
May 14, 2014 at 21:53:18
Specs: Windows 7 SP1, athlon fx 4100 QuadCore/ 4GBRam
This is an am2 mobo that has a peculiar problem. First some background info, this was an ebay motherboard to replace a dead one. It didn't work when I first tried it, couple of months after it was bought. This was back in 2012. Anyway a few days ago I decided to give it another shot. Reading about a feature that would let me restore a crashed bios Crashfree3 so I gave it a go. The thing posted to my surprise. So I installed Win7 on it and even had it reboot a few times. I had it in a "breadboard" setup basically it's box. When I saw the install go alright and rebooted a few times after I decided to put it back into the case.
This case doesn't have standoffs but more like bumps that the screws go into then I use the plastic standoffs for the holes missing bumps. My first suspicion was something in the case was causing a short, keeping it from posting. Took out the motherboard and breadboarded it again, again no post. Then the usual run of clearing the cmos, jumper and battery with just the bare essentials, still no post. While breadboarded I decided to try a spare gpu I had laying around, with nothing to hold the bracket I had to apply pressure to the gpu to hold it steady. Guess what happened next, the computer posted. I think the gpu is fried however as it never gets video, luckily this mobo has an onboard gpu. So holding pressure to the pci-e slot I can make the motherboard post. Hmmmmmm. When pressure is then released the video blanks out. So I thought maybe the integrated gpu is causing the short, held pressure on it and voila it posted. It has this weird spring plastic screw thing going on it's heasink so I thought maybe that was the problem. I put a shim on it to make the fit tighter, it didn't have any effect. Then I thought maybe the northbridge, same thing put pressure on it and it posts. Then I went crazy and decided to put pressure on the pci slot below the pci-e one, it posted. See the pattern?
Here's a picture. So any pressure in that general area seems to get the motherboard to post. The IC under the silver heatsink is the northbridge the black asus heatsink contains the gpu.
I guess what has me weirded out is why it would post w/o any pressure a few times then act like this. I've cleaned the motherboard out and inspected for any signs of malfuction, so far no luck.

Now more weirdness I forgot to mention. This motherboard was ebayed as a replacement for a fried one, same model. The cpu is an athlon 4500+ the energy efficient one ddr2 mem 2GB. I have already bought a replacement for this build, I upgraded to an am3 fx one. I was just messing around and thought that when I fried my mobo the rest of the components went with it. Seeing as how the gpu fried too. Faulty PSU blown caps on it caused my headaches the first time around with this mobo. Remember earlier when I was able to get it to post once I restored the Bios, this happened after being on for a few hours Crashfree3 thing only took a minute to complete but I didn't really expect it to work so I just left it and forgot about it. When I remembered I rebooted and the magical little post beep made me happy at least for a minute :P

So recap, flashed bios but left it on a few hours it posted. Installed win7 when that finished I put it back in case (was breadboared) then it wouldn't post. Suspected case was causing a short took out again and still no post. Wanted to see if it would post with a pci-e card and had to hold it down, motherboard posted (breadboard setup). Then suspected integrated gpu and shimied it still no post, but if I hold pressure to it, voila post.

I'm thinking of baking this sucker and seeing if maybe I'm a victim of microfractures in the solder. I've tried everything else. There doesn't seem to be any visible damage cleaned it with isopropyl alcohol, and only had a bit of dust I have read that debri can cause a mobo to short but all is clean now. The areas in red(from picture) are the ones that when pressure is applied it makes the motherboard post and boot held pressure long enough to see it load win7 successfully.

Has anyone experienced anything similar and maybe also fixed it?

Truth can become lie, but if lies become truth we're in trouble.


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#1
May 14, 2014 at 22:00:23
I would probably declare it not worth the pain and suffering and move on. I suspect the board is/was making contact underneath as you say with said case design. If it did work with a lot of shimming, would you trust it to last or be reliable? Is it getting grounded properly.

To err is human but to really screw things up, you need a computer!

message edited by HopperRox


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#2
May 15, 2014 at 00:58:22
Does the same thing breadboarded

Truth can become lie, but if lies become truth we're in trouble.


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#3
May 15, 2014 at 13:58:39
Most likely a poor connection on the board in that area - often difficult to find. Instead of pressing try tapping with an insulated object, that might locate it a bit closer. Something like a tooth brush handle would do. Often the largest soldered joints are the ones that first give most trouble. Look for a ring around the soldered area of components (a reflow then might help).

Always pop back and let us know the outcome - thanks


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#4
May 15, 2014 at 20:24:51
Yeah, sounds like to me the board was either A. unusually stressed physically or B. exposed to some very localized heating. Don't think it's worth the trouble really, but if you're willing to go for it, sure. Baking the board may or may not help; it could be an underlying issue with the board structure itself causing the disconnects.

Ideally you would have contacted the seller directly and asked about their policy regarding shipped dead parts; you might have been able to return it but being an ebayed part that's unlikely.

~oldie
Not everyone can decipher Klingon script...
chay' ta' SoH tlhe' vam Doch Daq


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#5
May 15, 2014 at 20:56:49
Thanks guys I'm going to see if replacing a suspect mosfet fixes my problem, seems I missed it while inspecting it. Looks to be leaking flux or something underneath it.

Truth can become lie, but if lies become truth we're in trouble.


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#6
May 15, 2014 at 23:16:28
Yeah, either a broken solder joint or maybe bad caps that sometimes work and sometimes don't. Are any of them leaking or looking puffy?

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