DIMM slots A1 and A2 aren't working due to possible AIO cooler installation error.

[Quixote]

Hello, everyone.

I've had my Maximus 7 Formula mobo for over two years now, and this is the first time I've had trouble with any of the DIMM slots.

I had 32 gb of RAM, but I've had to go down to 16 gb, placing two 8 gb sticks in the only two working slots, B1 and B2.

The system works fine on 16 gb, but I also do photo editing and creative work with this computer, so my previous 32 gb of RAM would obviously be ideal for me.


To explain what happened:

I had installed a new AIO cooler, an H115i from Cosair, and after that point, I began to get the 55 code on the mobo.

So, obviously, the code is likely related to that installation. It wasn't happening before that point. It occurred immediately after installation.


A couple of things I'm thinking happened, all of which are likely my doing and not any inherent defect of the board (again, because this wasn't a problem until immediately after the cooler's installation):

1. I inadvertently damaged some of the circuitry on the board that have something to do with slots A1 and A2 while installing the accompanying H115i backplate by either tightening the standoffs too much when installing the backplate or overtightening the nuts that fix the cooling unit on top of the CPU.

2. I somehow damaged some A1/A2-related pins on the motherboard's CPU slot when I tightened the cooling unit on top of the CPU. Not sure how that works, but I've read it is possible.


I have reseated the CPU. I looked the slot over and I'm honestly not sure if any of the pins are bent or not. My vision up close like that isn't great, so I probably need to get a magnifying glass in order to see it better.

I have also reinstalled the cooler unit and backplate to sit a little less tighter (while not too loose - it doesn't wobble).

Also, I should probably mention this: to make the Corsair-style backplate for the cooler sit a little more snug than it usually does, I used some very small metal washers to go between the standoff screws and the backplate. I put these washers on the backside of the motherboard. Usually, those backplates from Corsair don't fit snugly with the standoff screws alone. So, I wanted a tighter fit. This could be where I got in trouble here.


First, my question is, any thoughts about the above? Does it sound like I am the cause of the A1/A2 slots going out?

Second, if I am the cause, I assume that I can't RMA this board. If that is so, can I buy another directly from Asus? I'm not seeing a lot of places to buy this version, MF7.

Thanks for any help.

[Korth]

HiVizMan wrote:
Please reseat your CPU and CPU cooler. I see this often when the cooler has been incorrectly or unevenly fitted. Try with one stick in the furtherest slot from the CPU, work your way in to the centre closest to the CPU and check that each slot is working.

I agree with this. Most likely faults are:
- incorrectly installed CPU (bent or damaged pins) or incorrectly installed CPU cooler (uneven mounting pressure, not pushing CPU pins into proper contact with socket)
- 24-pin EATXPWR or 8-pin EATX12V power inputs not properly plugged in or PSU is failing
- bad or mismatched DDR3 DIMMs

You can try reseating your DIMMs and/or swapping your DIMMs around (and running a few passes of memtest) to determine if any of your DDR3 DIMMs have failed.
You can try using a different PSU to determine if it's the fault.
You can try remounting your CPU and CPU cooler. Since this is the thing you changed then it's probably the best thing to troubleshoot first.

DIMM contacts and DIMM sockets can be dirty (from handling, mostly) and have faulty electrical contact. They can be cleaned if necessary. But you should first confirm this is a real problem by isolating a particular DIMM (or DIMM slot) which always fails.

PSU connectors can have loose or wiggly pins which aren't making good contact (at either end, if the cables are modular).

[Quixote]

Korth...

So, in your opinion, is it more likely to be the CPU slot pins on the motherboard which are damaging and affecting slots A1 and A2 as opposed to my having over-tightened the standoff screws for the backplate and maybe damaged some of the board's circuitry to A1 and A2 in the process?

I realize you have no way of knowing, but I'm wondering about which one is more likely and how possible it is for me to actually damage the board circuitry itself by tightening those standoff screws too much.

[Quixote]

I took a look at my CPU slot on my M7F mobo, and I think I do see two darker and possibly bent pins.

Although, when I look at those photos close up, they actually don't look bent to me. They look darker, as if they are burned out.

Is that another possibility? I don't know.

Can someone take a look at this and tell me if you see what I think I see? Are those two darker spots
in the bottom left quadrant of the CPU slot actually a couple of bent and/or burnt pins?

I plan to get a good magnifying glass soon and take a closer look.

[JustinThyme]

place your CPU on a flat surface and make sure the corners are not bent up. Over tightening the heat sink mount can push down on the IHS too much causing the center to sink and the corners to bend up. The 7700Ks are extremely susceptible to this because the actual PCB is very thin. I had the same issue with a 7700K after installing a monoblock and pulled my hair out for awhile then while inspecting the CPU I noted two corners turned up ever so slightly. I was scared I was going to break it so I found a socket that would sit on the corners but not the IHS and placed it on a flat surface with the socket and 1lb weight on top and left it sit for a day. Put it in, tighten very easily on the block as in snug and like 1/16 of a turn more. Still running!

[Korth]

I always remove motherboards before installing/removing CPUs. Because I, too, am fearful of cracking PCB traces.

Yes, it is sometimes inconvenient (takes extra time) to fully remove and install the motherboard in chassis. And it's not strictly necessary - the motherboard substrate is fairly thick and can be bent/flexed a little with no damage - many people do it all the time. But gambling with the sheer density of critical traces in and around the socket seems to just be asking for trouble; the risk of failure is low, the consequence of failure is catastrophic.

I won't work in other peoples' computers if they didn't bother to use all the mobo mounting standoffs and screws - they say these things aren't needed and just add time to their hardware installs - or they've modified (cut away some structure of) the chassis to accommodate extra/bigger parts that wouldn't normally fit. More power to them if these lazy shortcuts work ... but I'm not going to be the one paying to replace their broken hardwares.

[Quixote]

Hey fellas.

Thanks for your responses.

I thought I'd chime in and report what occurred since I last posted.

It was a problem with the standoffs, but thankfully, I did not destroy the board.

Here was the issue: I stupidly used small metal washers on the back of the board to make the cooler unit fit a little more snugly over the CPU. The metal washers were likely interfering with the DIMM signal somehow, probably messing up the connection, etc.; they were simply crimping the traces on the opposite side via the simple pressure they exerted. I don't know. Either way, I removed the metal washers on the back, and voila. DIMM slots A1/A2 worked again. No problem.

I could have used rubber washers, but I didn't. I just thoughtlessly put the metal ones on. I know. Dumb. I'm no expert at this. I'm a noob when it comes to builds, or anything computer-related. Even if I had used rubber ones, I probably would have risked compressing the board too much. Who knows. I won't try either anymore since I obviously don't need them. The cooler unit, if fitted correctly, and if the standoffs are tightened according to the directions in the manual, then it's fine. It's snug and it doesn't wiggle over the CPU.

So, lesson learned.

If someone has the same problem in the future and reads this, maybe they'll benefit from my dumbassery.