NP355V5C new motherboard, keyboard not working

Hi, i just bought new(used) motherboard for my notebook(this http://forum.notebookreview.com/threads/samsung-np355v5c-graphics-card-not-working-rip.791310/).

I can't do anything now because keyboard is not working, even in BIOS.
What can i do now? Can this be because of BIOS? I live in Europe and i bought this motherboard from China if that matters for the keyboard.

Old motherboard is QMLE4 LA-8863P Rev: 1.0, new one is rev: 2.0

 

If the keyboard has died they are available on Ebay. Check first as that little ribbon connector can be tricky. Also if it gets even a litttle dirty the connections may not happen again causing issues.

 

But keyboard works on old motherboard.

 

Again those connectors can be an issue, been there done that. Now it could be the new main board has an issue as well.

 

I know. But connection is good. But before i call a new motherboard a faulty one i want to know the other options. If that can be caused by BIOS etc

 

Usually no but put in a USB keyboard and go through the options. FYI, if the connector on the main boarrd is bad it does not matter how many other keyboards you try you will just have too get another main board.

 

Ok, i will try to get USB keyboard from a friend tomorrow.

 

One thing I have noticed, ebay lists a rev 1.0 and rev 2.0 keyboard if that matters.

Rev 1.0
http://www.ebay.com/itm/HR-Serbian-...700001?hash=item41c2d652a1:g:EuQAAOSwSypY-jqv

Rev 2.0
http://www.ebay.com/itm/New-Keyboar...755130?hash=item2a3484f4fa:g:pPgAAOSwDNdVklvV

Even Rev 4.0
http://www.ebay.com/itm/Laptop-US-K...925870?hash=item41c100bf2e:g:OiEAAOSwdGFY2IYo

 

I have no idea what are you talking about now. There is no rev 4.0 of this motherboard, only 1.0 and 2.0. And there is nothing about version in those links ;o

 

I would not expect any inherent incompatibility between keyboard and motherboard. I've swapped the keyboards between two different versions of the NP900X4C (one UK and one Indian) without any problem. It's time to look carefully at the keyboard connector on the new mainboard (including any soldering on the other side of the board) to see if it looks OK.

Can you confirm that the rest of computer is working?

John

 

So trying different BIOS is pointless as the keyboard should always work in BIOS? Hmm i will check again this connector but i looked carefully before and everything looked good.

"Can you confirm that the rest of computer is working?".
What do you mean exactly? If you mean on this new one then i can't, im stuck in BIOS without a keyboard. But when i connect HDD or DVD then im stuck with a message about being unable to boot from those, so they are detected. All the parts work with old motherboard.

 

I just tested and the USB keyboard is working in BIOS. Does internal keyboard and USB keyboard work on the same controller on the motherboard?

 

Thank you for the additional clarification. Confirmation that the HDD / DVD drives are detected is by having the model number(s) shown on the BIOS setup screen. Can you get to that screen?

I suspect that the internal keyboard and USB keyboards have different controllers. The latter represents one of many data sources which can come through the USB interface while the former has to decode the signals received through the keyboard connector (which has far fewer contacts than the number of keys).

John

 

I just used USB keyboard to install a Windows 10 on this PC. Installed all the drivers etc. Keyboard is still not working, but its visible in Device Manager. What can i even do now?

 

I'm wondering whether there is a subtle hardware difference between Chinese keyboard / mainboard combination and their western equivalents which prevents interoperability. Perhaps the Chinese keyboard needs to create more character combinations so it is wired differently in a way that the computer can see the keyboard but not be able to read it. I've not read of this problem previously but I don't recall anyone using a Chinese mainboard as a replacement.

Anyone have other suggestions?

John

 

I just bought it from China. I checked and it's from NP355V5C-S01UK so its european model.

 

It is possible the keyboard header somehow is damaged or defective. Since the keyboard has onboard electronics the OS sees those as active and good. It seems the connection just is not happening. I had one header the was causing an issu and toook an eraser and cleaned the contact area of the ribbon carefuly, and that worked. Do so though at your own risk!!!!

 

Or if the keyboard worked OK with the previous mainboard then maybe the problem lies with the keyboard socket on the new mainboard. Look very carefully at both the contacts in the socket and the soldering of the socket onto the board. I have to be inherently suspicious of parts still available in the country of manufacturere this long after production (rather than a part remaining at a UK service agent).

If we fail to debug this problem then you've got a working notebook except for the keyboard issue and one workaround for that could be a rechargeable bluetooth keyboard.

John

 

Keyboard socket looks ok, nothing visible suspicious. But i just disconnected the keyboard, booted up windows and i still see keyboard in Device Manager as plugged in and working.

 

With the keyboard still disconnected, if you delete the Keyboard Device in Device Manager and restart Windows (or Scan for hardware changes in Device Manager) does the device re-appear in Device Manager?

If yes, it would indicate that the device (as seen by Windows) is based entirely on the keyboard controller on the motherboard, regardless of whether there is a physical keyboard attached.

If no (i.e. the device does NOT re-appear) you can re-connect the keyboard and see if it then shows up on next reboot. If it DOESN'T that would prove that there is either no connection to the keyboard or it is dead.

Great analysis!

 

Just checked, it is indeed always reappearing after uninstalling as connected and working.

 

Weird, and not something I have previously encountered. Perhaps the keyboard is hard-coded into the BIOS so it's automatically identified event if not connected. I know Samsung does this with display types (so changing to a display with a different resolution requires a BIOS edit).

John

 

I am guessing the Windows device shows up whenever a keyboard controller is present, regardless of whether a physical keyboard is connected. That would explain this.

If so, it just means we cannot use Device Manager to check the physical keyboard.

You can try this to confirm: In Device Manager, list devices By Connection (instead of By Type). Then find the keyboard device and see if there is a separate controller device above it.

 

Yes it will show as the device electronics are still there and operative so when the OS pings the device it answeres back essentially.

 

There is nothing about keyboard when i list this by connection. But i just did the same on other laptop(lenovo y700) and there is also nothing about keyboard there. You sure there should be something?

Someone advised me to do a bios chip swap from old motherboard to new. Does that even makes sense?

 

No, I was away from my PC (still am), those posts were from the top of my head.

I was merely wondering if there was a separate Keyboard Controller device in DevMgmt to which the keyboard device is connected. You confirmed there isn't. So no doubt (in my mind): A Keyboard device in Device Manager is merely a keyboard controller, not an actual keyboard.

Given that, we DO have indication that the keyboard controller is working OK. But we still don't have any indication that your new keyboard is alive and connected, including the cable and the connector(s).

I still like John's analysis that a keyboard out of China this long after production raises some doubts. I wish there was another way to test it.

 

But i got new motherboard, not keyboard.

He was doubting the motherboard, not keyboard. Keyboard is working fine with old motherboard.

 

When you say is working, you after putting in the new main board and the keyboard not working reinstalled the old board again just to boot it and be sure the keyboard was functional? Or do you mean that it worked before so it should work now?

 

It is working on my old motherboard. My old motherboard can boot system normally, only graphics chip there is dead. On my new motherboard the keyboard is not working at all.

 

Right, so you have booted the old motherboard with the keyboard since you have booted the new motherboard and that combination did not work correctly?

 

Of course. Keyboard is 100% working.

 

Yes, yes, that was a silly mistake on my part.

But the deductive procedure remains the same: (A) You know your keyboard is working, including the cable, because it works with the old motherboard; (B) you know the new motherboard is working, because everything seems to work with a USB keyboard; (C) you know the keyboard controller on the new motherboard is working, because it shows up fine in DevMgmt.

I say it has to be either the keyboard connector on the new motherboard or the traces between the controller and the connector.

I doubt it is a BIOS problem, but I guess it cannot be ruled out. You could try downloading and flashing the latest BIOS using the guide in this post.

Edit:
Oh, and I just remembered, PS/2 mouse/touchpad are usually handled by the same controller as the keyboard, so if those are working with the new motherboard, that further strengthens the case that it's either the connector on the motherboard or the traces.

 

I did the BIOS update already, nothing changed. But they wanted me to change the bios chip from my old motherboard to new, not just flashing the bios.

Yes, touchpad is working.

I guess we are done here. I can't fix that. I will ship it back. They said they will try to fix that(they want to send them my keyboard too, because they tested it with their keyboard before shipping to me and it was working). Now i will need to wait probably a month or longer before i get it back. Will say what was the problem later.
Thanks everybody for help, much appreciated.

 

If the chips are socketed you could try swapping them. But I am guessing they are soldered -- or you would have tried it already.

Yeah if it's the connector or traces, that's hard to fix.

But don't take a final verdict from me. I am not really the hardware guy here, I only barged in when you mentioned that bit about the keyboard showing up in Device Manager

 

Yes, send it to them. That is the best option. It has to be some break in connection from the keyboard to main board and it could exist in the cable or its connects. It is hard to diagnose a hardware problem if you do not have it in hand.

 

Hello, unfortunately i wasn't home for a long time to check the new motherboard. They send me another motherboard and said the old one was broken. They didn't say what was broken exactly.
So i assembled everything and its working but now there is another problem...

It's "Plugged in, not charging". Uninstalling battery controller by device manager and restarting helps for a short time. Sometimes if you unplug and plug again it will no longer charge, or if you put the laptop too sleep. Battery calibration in BIOS also doesn't help.
Anyone know what can cause this?