ESD'd RAM Channel 2

[Joshua Martin]

Ok, so even after taking the appropriate precautions, it looks like my channel 2 was ESD'd. After changing components over to my new PC case, it will not work anymore at all if RAM is inserted into one of the channel 2 slots. The only thing I can think of would be ESD.

I guess I'm going to RMA the board. Do you guys know if that would be replaced under warranty if it is ESD? I hope so. Can they tell if it was ESD that caused the issue?

My main question is, until it gets RMA'd, should I stop using my PC until then? Can it cause more problems with other components after? So far just channel 2 isn't working and I've been using it for a few days after and everything else has been working fine.

I thought I had taken the appropriate measure to avoid ESD, like keeping the PC plugged into the receptacle (with PSU off of couse) to keep it grounded and grounded myself before working on the components to discharge any electricity. Now i'm worried about working on my PC in the future, in case I mess something else up :/

Thanks for the help guys!

 

[InvalidError]

The motherboard does nothing more than provide copper interconnect between the CPU's integrated memory controller and the DIMMs. I do not think there is anything on the motherboard itself that can be damaged by ESD on the DIMM slots. If something got zapped by ESD, it would be either the DIMM or the CPU.

To reduce the risk of ESD, you need to maintain contact with the case in one way or another whenever you bring components in or out of it. I usually do this by resting my forearm or a wrist on the metal frame as leverage and as a stabilizer when I line up parts before dropping them in. For parts outside the case, you want to put those on a dissipative bag and touch the bag before touching the parts and pick up parts by metal brackets whenever applicable.

 

[Joshua Martin]

The motherboard does nothing more than provide copper interconnect between the CPU's integrated memory controller and the DIMMs. I do not think there is anything on the motherboard itself that can be damaged by ESD on the DIMM slots. If something got zapped by ESD, it would be either the DIMM or the CPU.

To reduce the risk of ESD, you need to maintain contact with the case in one way or another whenever you bring components in or out of it. I usually do this by resting my forearm or a wrist on the metal frame as leverage and as a stabilizer when I line up parts before dropping them in. For parts outside the case, you want to put those on a dissipative bag and touch the bag before touching the parts and pick up parts by metal brackets whenever applicable.

Thanks for the quick reply!

So you don't think it's an ESD issue? If it was ESD, would the whole board have gone bad?
Basically, If RAM is inserted into slots 2&4 the PC won't post, it just power cycles. It was working fine before I moved parts over to the new case. I didn't remove the RAM either, while switching the motherboard over.

Thanks for the tips and I'll remember that. I generally touch the PSU or metal on the case every few minutes while working, but I've never stayed in contact with metal while pulling the parts. I'll definitely remember that! Thanks again.

 

[InvalidError]

So you don't think it's an ESD issue? If it was ESD, would the whole board have gone bad?

I do think ESD damage is probable. But not on the motherboard.

Most pins on the DIMM slots are either ground pins (about half of them) or directly connected to the CPU. If the ESD hit a data/control pin, then that ESD went straight to the CPU's memory controller. If something got damaged by ESD, it was most likely the CPU - a part of the integrated memory controller that manages channel #2. That would be why your PC only boots when only channel #1 is populated. With only #1 in use, the damaged #2 controller is inactive in that case.

 

[Joshua Martin]

Most pins on the DIMM slots are either ground pins (about half of them) or directly connected to the CPU. If the ESD hit a data/control pin, then that ESD went straight to the CPU's memory controller. If something got damaged by ESD, it was most likely the CPU - a part of the integrated memory controller that manages channel #2. That would be why your PC only boots when only channel #1 is populated. With only #1 in use, the damaged #2 controller is inactive in that case.

Is there a way to run a test within Windows to test the RAM channels? That way I'd know if it was my CPU or board? I'd rather not waste time shipping my board off just to find out it's the CPU.

Thanks for all of the info, I've definitely learned a lot just from this post.

 

[Joshua Martin]

Let me start from the beginning just to make sure you have all of the info.

I had purchased a new full tower to replace my mid-tower. When I got the tower in and removed all of my PC parts from my old case. I did not remove the RAM (4x4GB G.Gkill Ripjaw) or H50 liquid cooler from the motherboard. Once everything was installed and I tried turning it on, it wouldn't post but would just power cycled. After narrowing it down to RAM, I started removing RAM to determine what it was.

Process:
Put RAM in slot 1 = Booted fine
Put RAM in slot 1/3 = Would not boot until changing XMP profile to "disabled" in BIOS
If any RAM is inserted into slots 2&4 it will not boot.

All RAM was tested in slot 1 to ensure they're all working correctly.
Just looked at the diagram for my board and Channel A (slots 2&4) isn't working. Channel B (slots 1&3) is working fine.

PC is seemingly working fine with RAM in slots 1&3.
Hopefully, this will help narrow done the issue.

Thanks for the help.

 

[InvalidError]

Is there a way to run a test within Windows to test the RAM channels? That way I'd know if it was my CPU or board?

If putting RAM in slots 2/4 causes no boot, then there is no way to boot into Windows to do any further testing.

As I said earlier, there is no electronics on the motherboard for ESD to fry. All it does is provide direct electrical connections between the CPU socket and DIMM slots. Any ESD that hit a data/address/control pin on the DIMM slot would go straight to the CPU.

If you banged the board while moving it between cases, you might have damaged a trace. Shaking the CPU could also have broken contact with socket pins, so you could also try re-seating the CPU just in case. Warping the motherboard could have broken some solder joints or vias too but I doubt that sort of fault would cause the PC to refuse booting altogether, I would expect it to generate memory check errors during POST. If there are no visual signs of anything having gone wrong with the motherboard, such as scratches, and re-seating the CPU yields no improvement, my best bet would be on the CPU.

 

[jsmithepa]

If you feel like doing this... use a loupe and a flashlight and inspect the memory slot to make sure there is not a piece of dirt stuck in there. Otherwise RMA it, just tell them memory slot broke, no need to divulge too much info when you are not even sure.

 

[Joshua Martin]

Ended up doing A LOT of reading up on memory channels not working and found 1 other instance on the net where this guys heatsink bracket was hitting up against the case, shorting out the memory channel. So, I decided to double check mine and make sure nothing was shorting on my board.

So I pulled the motherboard out and noticed.. one of my standoff screws was 1 inch from the hole it should have been in.. It was hitting the back of the board causing it to short out. Double checked this time and put everything back together and it's working fine now. Can't believe I let that happen...
I'm glad it didn't cause any damage. >.<
Been in IT for a couple of years, turns out you can't double check things enough..


Thanks for ALL of the help and info. Definitely learned a lot from this topic.

 

[InvalidError]

Misplaced studs. Yup, that would do it too. It never happened to me since I count the number of holes that line up with the motherboard tray, only install that many and count my holes again when I put the motherboard in to make sure all my studs are lined up and accounted for.

 

[jsmithepa]

Well don't you feel silly. 😀

I always felt ESD issues are from the olden days. If it was so sensitive, we would have a lot less on-top-of-carpet builders in this forum.

 

[InvalidError]

I always felt ESD issues are from the olden days. If it was so sensitive, we would have a lot less on-top-of-carpet builders in this forum.

Parts are still vulnerable to ESD but when they are assembled on a board, the chances of directly zapping an IO pin are much lower. Also, most modern chips have some degree of clamping between their IO pins and IO supply/ground due to built-in bus termination and programmable impedance circuitry so when ESD does come through, most of it will be redirected to PCB power/ground planes. They may be more difficult to harm but they still can be.