Solved Thinkpad E470 Keyboard Problems (spamming random key and not working properly)

Hey everyone,

I hope I've found the right place for my issue and sorry in advance for potentially writing in bad English (not native).
I had an incident with my Lenovo Thinkpad E470 several months ago where I accidentally spilt some liquid over the keyboard. I hadn't been using it for a while and didn't try to turn it on after spilling liquid over it, I just tried to let it dry somehow. Now I wanted to use it again and the keyboard didn't work.
I bought a new keyboard and successfully (I think) replaced the old one. I may wanna say: In general, the notebook perfectly works. However, there are two issues: The Thinkpad randomly spamms the key "<" and only this one whenever I try to type something somewhere, making it impossible for me to use it. Also, some of the keys don't work at all, for example, "p", "o", and others (both issues both with the old and new keyboard). Here's the thing that's weird for me: "<" was also being spammed while there was no keyboard built-in at all, leading me to think that not the keyboard but something else is broken, which makes it probably worse. However, I still have some hope that this is somehow directly or indirectly fixable since, after all, the only problem is that I can't type properly.
I've tried:
- uninstalling keyboard and refreshing drivers
- connecting external keyboard which works but doesn't resolve the "<" issue, making it still impossible to use the laptop.

Thanks in advance!
Nils

Hey Bruce,

thank you very much for your answer, I already appreciate your effort!
I am pretty sure I undid both of the ribbon cables and had no keyboard attached at all and the random typing was still happening. However, I will confirm this and try again on Monday when I am back home.

It would be already helpful if I could somehow 'forbid' my laptop to type at all - whatever may be the reason that causes it. Then, I would at least be able to properly use my laptop with my mouse even though I still wouldn't be able to type, which would be somewhat okay since I don't use it too much anyway. The way it is now, even surfing just with my mouse is hard with the random typing. I don't know if what I said is possible or makes any sense at all.

However, as I said, I will try once again next week and let you know. Thank you so far, and have a nice weekend!
Nils

Bruce said:

g'day Nils and welcome to the forums.

sadly, liquid spills on laptops hardly end well.
since you have replaced the keyboard and state the random typing of < is still happening and even when no keyboard was attached, this would suggest the liquid has damaged other circuitry.

just checking, when you say it wasn't attached, you removed the keyboard completely from the laptop - that is - undid the couple of ribbon cables from the underside of the keyboard that run to the main board?

Click to expand...

Hey,

I just tried again: Even with the keyboard completely removed from the mainboard the random typing is still happening, still only "<".
One interesting thing I noticed, even though I don't know it matters: While the random typing usually happens all the time when I enter a 'field' you can type in - so windows search, browser search bar, documents etc. - it didn't occur when I had to enter my PIN after restarting the device. Normally, I can't even type with the on-screen keyboard - in the start menu, it works without the "<".

Kind regards
Nils

Bruce said:

as weird as it is, the fact this only started after the liquid spill would indicate the cause, however weird the effect.
somewhere else along the circuitry highway, something has gone pear shaped!

Click to expand...

Well, I guess I gotta accept my defeat then. I just hoped since everything else works perfectly that I could somehow trick the laptop - at least into not allowing it to type or output any keys at all. Thank you for your help; if I should stumble onto a creative solution at some point I will let you know.

Hey, thanks for coming in. I will try to clarify:

I tried using the external keyboard in different ports. In all cases, so old or new inbuilt keyboard connected OR completely removed and with an external keyboard connected or not: "<" keeps being auto-typed every time I enter a typing field (so not even only "now and then" but constant spam as soon as I try to type something). What I just realized: The reason it does not so when entering my PIN is probably that the PIN field is a number-only field where it is 'not allowed' to type anything but numbers - hence no "<". Don't know how that helps though.

Also, with the inbuilt keyboard (old or new), some keys don't work (o,p, some others). They DO work with the external USB keyboard. Still, in both cases "<"s everywhere. Since I can't type properly, it is also not possible for me to do a factory reset since my password is required and even though I can produce the letters with the external keyboard, the "<" makes it impossible.

I don't know anything about hardware but the problem seems to be that the liquid damaged something 'deeper' than the keyboard, so where the interface between the keyboard and the motherboard is or something like that (sorry, that probably sounds terrible). This causes the constant "<" typing every time the cursor is in a typing field, so every time it is possible to output "<".

Is there some way (again, I don't even know if the question makes sense) in terms of hardware or software/BIOS to completely deactivate the inbuilt keyboard function, so not only remove the ribbon cables or deactivate it in device manager (doesn't seem to work properly). My (probably naive) imagination is that we somehow get to completely delete the device's own keyboard input/output function, hopefully stopping the "<" spam and allowing me to use a USB keyboard.

Sorry for the layman speech.

Sorry, I thought I had everything. To be honest, I don't entirely know. It happened when I had a few people over and someone put a glass where he wasn't supposed to put it..... Pretty sure it was some juice. I was in another room and noticed a few minutes later - tried to turn it upside down after drying it with clothes and stuff as best as I could in that situation.

Hey, sorry for not answering. Right now, I am on a work trip and my Thinkpad is at home. Once I am back home, I will try to disable the keyboard in BIOS, as you suggested, @Bruce. Apart from this, I think there is not much more for me to do so you can close this thread if that was why you asked. Thank you all again for your ideas and help!