Question Motherboard requires 2 ram sticks to boot and only shows half of the memory.

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PedramCarter

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I got a new motherboard, I had the ab350 gaming (first 1) and it refused to turn on one day. I installed my new motherboard (msi x470 gaming plus) and it beeps at the start and won't boot with 1 ram stick only installed and need both of my ram sticks to boot and only shows 7.95GB out of 16GB.
I have tried resetting cmos I have updated my bios to the latest and before it would show 16 GB and 7.95 GB usable now it only shows 7.95GB in new bios and won't even acknowledge 16GB.
Did I mention I tried to test each stick and it doesn't boot with only 1 and needs both, before bios update I would get a message to say memory modules found in non optimized memory slot which was in the correct one (a1 and b1) it would tell me to put it in a2 b2 which I would do so and it would tell me to do A1 B1 this time.
My ram sticks worked last time and there's no sign of physical damage I have taken extra care, the fact that it needs both of them to work is just weird but I guess they must work if its the case, I have done Ram test also on windows and no issues.
I also did OC and tried to set my ram to 2666 and voltage but it always shows as 2111mhz rather than 2666 even with overclocking.
my specs

ddr4 16 GB (2 X 8) Corsair Vengence LED 2666 1.2v
Asus rx480 8GB
Ryzen 7 1800x
MSI X470 Gaming plus
corsair 8110i cooler
SSD Blue 500gb.
 
and yes I am absolutely 100% serious, the issue my friend had was all due to the CPU stand offs not being proper and it must of caused too much pressure on part of the CPU. when the problem was first discovered his OS(windows 10) was showing he had 8Gb of Ram however 4Gb was 'hardware reserved" .. so he called me and I went to check out the PC, I did everything I could think of and couldn't get windows to use all the ram . and in the Bios it was only showing 4Gb available on a single channel. so I tested each stick and individually etc. and it all was looking like the DIMM port being bad. someone had suggested reseating the CPU , so as a last resort I tried that. at first I left the CPU cooler just sitting on the chip, not expecting any promising results. however this time the bios showed all 8Gb of Ram. so I thought ok .. maybe somehow CPU came loose (no clue how but hey .. it was working.. ) or so I thought.. once I tightened down CPU cooler again it went back to how it was, only using half the ram.. so after that I realized it had something to do with the cooler. I then took it off and unmounted board etc.. and noticed the standoff wasn't quite right. so once that was fixed, everything worked perfectly. only thing I can conclude is that there was too much pressure on one part of the CPU, Pins etc.. making the one DIMM slot unusable.

Maybe it was putting some kind of pressure on the mobo, and as a result making the DIMM slots not function correctly. I don't see it, but maybe your right. I take my disbelief back, I guess it's possible.
 
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Gfost73

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Maybe it was putting some kind of pressure on the mobo, and as a result making the DIMM slots not function correctly. I don't see it, but maybe your right. I take my disbelief back, I guess it's possible.
very well could of been that too, maybe bending board due to cpu cooler backplate not being correct or standoff twisting board somehow,.. I really cant say 100% what caused it.. all I know is that everything lead to the CPU cooler being improperly installed that caused the problem, because once it was installed correctly (and all I could see that was wrong was the screws wernt lined up 100% properly and a standoff screw wasn't tightened proper , (they installed a cooler master hyper 212) but once that was fixed, and cooler was reinstalled properly, it all worked fine and has worked fine since. I would of maybe thought it was the reseating of the CPU , if it wasn't for the fact that when cooler was reinstalled (first time) the issue persisted. and once the cooler was installed proper, it stopped. shrugs.. why though?.. no clue.. just know it did hehe
 

Gfost73

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I am starting to feel that maybe one of yoru DIMM slots are just bad.. I would have to agree that I cant see how installing windows again will fix the issue as the issue isn't OS related (or wouldn't think) however I guess its possible that windows would install drivers maybe for the RAM but I always thought that was kind of prebuilt into the Bios. . do you have any other machine you can test the RAM on to verify that they do work together? short of that I'm not really sure what to suggest, Try reinstalling windows see if that works, reset Bios.. (unplug PC, remove CMOS battery wait a min or two.. put back in and see if it reset. might also try to get ahold of 2 other RAM sticks known to work to see if they work in yoru machine .
 

Does it work

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I have reinstalled windows and it still shows as16Gb 7.95 usable .
I know it might sound silly and you have tried it, but just check your manual to make sure you are populating the correct dimm slots, sometimes boards have different layouts to others based on the version (v1 vs v2 of an asus board a while back went from AA BB to AB AB for example). Could simply have 1 in 1 channel and the other in the other channel and its not accessing it properly.
 

Gfost73

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its for sure a strange one .. I was going to suggest making sure you have them in the right slots as well but where you said you had tried them in different ones etc I hadn't.. is it possible there is some dust or something in the slot itself..? perhaps try blowing them out with air to make sure no lint etc got trapped in them. if you had a way to get some RAM you know 100% works to test or a way to take your RAM to someone who knows their board 100% works.. that may be ideal. or as suggested above make sure the RAM are in the right slots maybe looking up on webpage for board be best to see if any bios updates or RAM updates etc.. cuz this ones a tough one lol.. but I think its boiling down to bad RAM or DIMM.. or user error installing in wrong slots (unlikely though)
 

Gfost73

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I checked your manual for that bopard and it says to use DIMMA2 and DIMMB2 which you said you had. b those are slot closest to the 24 pin power and the 3rd.. ( or the 2nd from CPU and 4th depending how you look at it hehe) .. but if they are in those slots .. and it still has issues,, well im at a loss myself
 

PedramCarter

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Did you clear CMOS after the bios update?
Pressed the cmos button, did not remove the battery I pressed the button once for 10 seconds and multiple times, is there a certain way you have to do it?.
Maybe it was putting some kind of pressure on the mobo, and as a result making the DIMM slots not function correctly. I don't see it, but maybe your right. I take my disbelief back, I guess it's possible.
I tried that, maybe the pins are damaged on the socket I'm gonna try get a replacement at least I will know if it's the motherboard or not.
 

PedramCarter

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I know it might sound silly and you have tried it, but just check your manual to make sure you are populating the correct dimm slots, sometimes boards have different layouts to others based on the version (v1 vs v2 of an asus board a while back went from AA BB to AB AB for example). Could simply have 1 in 1 channel and the other in the other channel and its not accessing it properly.
I have tried every slot combination nothing really worked, when I put it in anything except A1 B2 or A2 B2 it doesn't boot at all and even if it's 1 stick still doesn't boot or even get to bios .
 

PedramCarter

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I checked your manual for that bopard and it says to use DIMMA2 and DIMMB2 which you said you had. b those are slot closest to the 24 pin power and the 3rd.. ( or the 2nd from CPU and 4th depending how you look at it hehe) .. but if they are in those slots .. and it still has issues,, well im at a loss myself
Yeah correct might be bent CPU socket pins like people have mentioned, hopefully it's not some kind of incompatibility with the ram sticks and the board, this weekend I will take another trip and pick up the same board for an exchange, I will keep updated.
 

PedramCarter

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When you test the sticks individually, are you using slot A2 to boot and do you reset cmos before booting?
ive seen a similar issue before where the Bios wasn't seeing both RAM modules.. and in that instance the CPU cooler wasn't installed properly, was putting too much pressure on the CPU, I discovered that was the fault by mistake as I was going to replace the board for the person, but once the CPU cooler was installed properly it worked perfect
Out of respect and to show appreciation for your efforts and time, I thought I update you guys on the situation, so I took the motherboard back and the technician confirmed it was faulty swapped for the exact same one again.
Set everything up and bam I have 16GB, I'm not gonna install windows again seen as it's exact same motherboard, right?
 

Gfost73

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Maybe it was putting some kind of pressure on the mobo, and as a result making the DIMM slots not function correctly. I don't see it, but maybe your right. I take my disbelief back, I guess it's possible.
I just stumbled on this video , and was shocked to hear what he said @ the 7 min 45 second mark, well that's where he starts.. but I guess improper mounting of a cooler can make DIMM slots not work LinusTech