Strange Issue With Keyboard Keys & RAM Memtest Errors

Hello,

I'm having a strange problem with my current laptop (Samsung NP900x4c); and also having a very hard time diagnosing the problem. I'm really hoping that this forum could help me as there are some smarter people than me in here.

Here's what's happening:

A month ago, I noticed that when my system was under heavy load (running warm & using lots of resources), that a three or four keys ("y" "k" "h") on my keyboard wouldn't function properly. By that, II mean that the key I typed wouldn't input the letter when I pressed the key. However, if I pressed it a few times it eventually would input the letter on the screen. Also, if I held the key down for a while, it would eventually type the letter.

However, this issue only seems to show up the computer has been running in Windows for a little while. When it does seem to randomly show up, just closing some programs (or restarting the system) would resolve the issue immediately. Right now I am having no problems at all with it while typing this post because the system hasn't been running for that long.

Again, The strange part about this is that it doesn't happen all the time. It only seems to happen after windows has been running for a while (w/o a power down) & when the RAM and CPU was under heavy load. Also, it's just a few keys (and always the same ones)

What I've tried in order to diagnose:
1. I tried plugging a USB keyboard in when the problem arises. USB keyboard worked fine.
2. I also tried using the on-screen keyboard when the problem arises. On-screen keyboard worked.
3. I also tried resetting the keyboard ribbon to the motherboard.
4. I also tried deleting the keyboard driver and restarting.
Note: There is no specific keyboard driver from the manufacturer for this laptop

Based on this, on paper, one might think the keyboard is bad.

However, I am still not 100% sure the keyboard is what needs to be replaced. The reason being is that only happens at random times when the laptop is under heavy load (and it runs warm/hotter). There also doesn't seem to be any problem with the with the responsiveness of the keys when it's not happening. Everything works exactly like it should when the problem isn't occuring. But whenever I start loading a bunch of tabs and a few resource intensive programs, it sporadically comes back and articles I type end up having words without the "y" "k" "h" and "v" letters in them.

I thought perhaps it might be due to a RAM issue, motherboard, or CPU issue.

So, I also tried;

1. I tried re-seating the ram in their slots.
2. I did a windows memory test and it resulted in some errors
3. I also did a RAM test with MEMTEST86 and it resulted in 101 errors.
Note: I never have any issues with blue screens, restarts, or anything of that nature.

Replacing the keyboard on this laptop isn't as simple as buying just a keyboard due to the design of this system. It would require a new base assembly for over $200 and a complete breakdown of all the components. Additionally replacing 16gb of laptop ram isn't cheap either (as it seems I am having RAM).

So, I really want to properly diagnosing the problem (if only one) before I make any decisions to buy different parts (to repair it); or decide to go buy a new laptop all together (if it's more cost effective).

Does anyone have any suggestions as to how I should proceed in order to make a proper decision and not blow money on a different laptop. I also really love this laptop and don't want a new system with shitty windows 10.

Thank you so much in advance. This forum is great.

Hello LouieP9086

LouieP9086 said:

Hello,

... I noticed that when my system was under heavy load (running warm & using lots of resources), that a three or four keys ("y" "k" "h") on my keyboard wouldn't function properly. ...

Again, The strange part about this is that it doesn't happen all the time. It only seems to happen after windows has been running for a while ...

It could be that it is heating up under heavy load. A Laptop Cooling Stand or a Laptop Cooler is the best available way of keeping the NP900x4c cool. With such a cooler in place you can see if Windows runs for longer before the issues occur.
Also keep the laptop out of range of direct sunlight. Putting the laptop in the shade will ensure that the operating temperatures are kept lower, and thus the electrical characteristics are maintained at within normal levels.
A Laptop Cooling Stand might be the best option for helping you diagnose your laptops issues and for avoiding having to replace an integrated keyboard.

It sounds like something is eating CPU cycles.

When it happens again check task manager for a process that is high on CPU resources.

Thanks for the advice. It's very frustrating.

The keyboard operates just fine under low load, especially when I put it in sleep mode when not in use.

When it happens, I noticed about 1/2 of my ram is being used and as far as the CPU, the "maximum frequency" will be high.

Do you have a temperature monitor?
I use Open hardware monitor.

ownload https://openhardwaremonitor.org/file...0.8.0-beta.zip
Expand to C:\Program Files (x86)\HardwareMonitor
Execute OpenHardwareMonitor.exe.
Under options set to run on Windows start.
Right click on Temperatures - CPU package - Mark Show in tray - Show in gadget

That is a bit hot. Your easiest solution would be to do what iko22 said -- get a cooling stand to put the laptop on. This would make it run cooler by providing plenty of ventilation to the bottom of the laptop.

Also, you could get a small keyboard to use with your laptop, something like this:
https://www.amazon.com/Keyboard-Port...3MX8C68GSNGDDH

Something this small would likely fit in your laptop bag, making it easy to bring with you.

I am noticing this happening at random times when it's not hot at all.

It's really a strange issue and really having trouble diagnosing it.

LouieP9086 said:

I am noticing this happening at random times when it's not hot at all.

It's really a strange issue and really having trouble diagnosing it.

The it sounds more and more like a keyboard issue - either it is faulty or the keyboard installation was not correctly carried out.

As you have a laptop device, there are very few tests we can do and communicate on-line. Try repeating a re-installation of the keyboard, or running Memtest for 8 passes. If you run Memtest again, take a photo of any results that you obtain through this test, and post the results to this Forum.

Thanks for the reply. You guys are great

iko22 said:

If you run Memtest again, take a photo of any results that you obtain through this test, and post the results to this Forum.

Ok....Will do this....it took a while to run last time. Will do it again as soon as I get the chance

iko22 said:

Try repeating a re-installation of the keyboard, or running Memtest for 8 passes.

What do you mean by a "re-installation of the keyboard". I've tried re-connecting the ribbon cables to the motherboard and deleting the keyboard driver.

iko22 said:

The it sounds more and more like a keyboard issue - either it is faulty or the keyboard installation was not correctly carried out.

This laptop has worked fine for me for several years, right up until the last 2-3 months (which is very untimely)

Any chance this could be caused by a faulty motherboard?

I can't afford to waste money. So, I don't want to get into a guessing game with the hardware that needs to be replaced and start buying replacement parts in trial and error. I am really not noticing anything consistent with regard to the CPU usage or RAM usage when it happens (or even the heating).

It only seems to happen with these keys; "y", "h", "k", "x". When it does happen, if I cycle through those 4 keys (and tap each of them a few times), presto! All the keys start working again. Right now, I am typing just fine (including those keys). But the issue always seems to come back at weird times.

This happens even when I don't even move the laptop from the surface it's on, which makes me think it's not an issue with the keyboard at all (but another component)

Any other suggestions to narrow it down, please let me know.

It is seriously driving me mad trying to diagnose this.