P8Z68-VLX Memory Slot 3 & 4 Don't Work After Installing Coolermaster Hyper 212 Evo

[suntower]

I have an ASUS P8Z68-VLX mobo with an Intel i7 K2600 and 16GB of Mushkin DR3 1333 memory (4 sticks all matching.)

I finally got tired of the CPU fan noise so I swapped the stock CPU fan with a Coolermaster Hyper 212 EVO. This required me to remove the mobo from my Antec mini-tower. And it's been downhill since.

The replacement -seemed- to go smoothly, but when I powered up, I got no video. So I tried the old 'remove the battery' trick and only using 1 stick of RAM at a time. And it booted. So here's where I'm at.

I have tried every combination of sticks. ANY 2 sticks in the first 2 slots will boot with 8GB. But the moment I add a stick to the 3rd or 4th slots, it won't post. The DRAM memory light stays solid red. I tried hitting the MemOK button, but it reboots and then blinks endlessly... never finishes.

Now before I swapped fans, I had used the AI Tweaker and so the mobo was OC'd -slightly- but I hadn't paid attention to it because it was set to 'Auto'. I thought that maybe this was causing the problem so I've tried resetting the BIOS (with 2 sticks) to 'Defaults' and 'Easy' but nothing seems to help. The moment I add back a 3rd stick the DRAM light comes on and it won't POST.

So... It looks as though the DRAM is OK, but -something- happened. How do I troubleshoot this? Could I have somehow messed up the mobo in such a specific way? Or is the overclocking still somehow affecting things?

Is there any way to track this down a little more conclusively? I've tried disassembling the mobo and re-seating a bunch of times... same results.

Is it likely that simply installing the cooler (the backplate) is what screwed things up?


TIA

[deejayburnout]

Is there any thermal compound in any of the ram slots. Might be causing an issue? What about the CPU? Did that maybe get dislodged while removing old cooler.

[suntower]

An update. I took the ASUS tech advice and removed the mobo and the Coolermaster backplate. And I think I see the issue.

There is a noticeable burr on one corner of the Coolermaster backplate which dug into the back of the mobo and appears to have nicked just deep enough to scratch 1 or 2 of the copper traces. It -may- be a red herring, but my totally WAG is that these traces are what connect DIMM slots 3/4 to the CPU.

Normally, I'd just chalk it up to me being careless, but the corner of the Coolermaster backplate is -clearly- burred. My guess is that I didn't notice it because the side you see (which doesn't contact the mobo) is perfectly smooth.

I'm hoping it's such a clean 'incision' that nothing else is messed up. If that's the case, I'll just suck it up, buy 2 8gb sticks and move on. In the back of my mind, though, I'll always be wondering a little.

Also, I feel like Coolermaster should pay me for the cost of 2 new sticks, but I'm sure there's little chance of -that- happening. (sigh).

[aramil]

Loosen up the fittings on the 212, having them to tight can bend the main board meaning that the ram may not be making proper contact.

Also make sure the back plate clears all components on the rear (ie no shorts/touching electronics)

Reseat the CPU just in case the pins are not making proper contact (also a good time to check for bent pins on the main board)

[ERU]

I used to use 'Silver Conductive Paint' to reconnect PCB traces when I cut them on purpose for over-clocking. Worked every time for me.

[suntower]

Interesting idea. How -precise- can you be with the Silver Conductive paint? The 2 traces that are broken are -really- close together.

The problem is that we -need- that PC in service. So I'm going to try to put 1x8GB sticks in it to get back to 16gb. If I need to take it out again, I'll think about giving that a shot.

[rapidracer10]

Very unfortunate thing to happen. Doubt it but did the ASUS tech say anything about RMA or warranty. I presume its finished but cant CM do something about it as their product possibly damaged it. May be a long shot