Keyboard issue never seen before

Crocodeal

Commendable
Apr 30, 2016
6
0
1,510
0
Hello,

Ok, this is an odd one. When I type and press some keys in a certain order, some other keys are typed in between. This only happens if I type fast (I type above 90 words per minute). Let me show you an example:

Typing del I get deol
Typing deo > delo
Typing rfl > rfol
Typing cdl > cd.l
Typing vfl > vf.l
Typing cem > ceum
Typing dea > deqa

(so you can see many combinations ending in the "L" key cause problems for some reason)

You can see the keys wrongly typed in between are always close on the keyboard to the last KEY in the combination del = deol (o is close to L). rfl = rfol (o is close to L). cdl = cd.l (dot is close to L) dea = deqa (q is close to a).

This happens only if I type really fast. If I type slowly "del" (by slowly I mean casual, not crazy slow) - there's no problem, it writes "del" or any other combination perfectly fine. Even typing these combinations fast, 1 out of 10 times they are typed OK. The laptop is a Dell Inspiron 7570 with Windows 10.

So, keep in mind it only types another letter/key only in 3 or 4-keys successions and ONLY happens if I type fast (so most of the time). NEVER noticed a problem with a single key or a 2 key combination.

Another example, let me type "dekl" or "delk" fast a few times to see what we get:
deikl deilk deilk dkl deilk deikl deikl dilke dilke dilke diokel deikl deilk.

Weird. Let me type "DEKL" with shift pressed down a few types to see what we get:
DEILK DEIOKL DEIKL DILKE DEILK DEILK DEILK DIOKLE DILKE DIOKLE DEIOL.

Typing many other 3-4 keys combinations really fast works perfectly fine. Only happens for certain combinations, only happens if I type fast. If you need other combination examples I can try some more and let you know.

Your help is much appreciated! Thank you!
 

stdragon

Proper
Apr 5, 2018
94
0
160
29
Years ago, I spilled some water on a Unicomp keyboard. I let it dry out for a week, but I had a similar issue. Pressing multiple keys or even a single key gave miss registration typos as I was typing.

Honestly, I'd replace the keyboard. To verify, just plug in an external USB keyboard. If the problem goes away, you now know factually you have ether a bad keyboard or a problem with the motherboard receiving the signal properly from the ribbon cable. It's really that simple.
 

stdragon

Proper
Apr 5, 2018
94
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Depends on the laptop. Some laptops can have the entire keyboard replaced under the palm rest. They're not expensive, and can be found between $16 and $21 in most places.

It could also be a loose ribbon cable connection. If so, you can take the laptop apart and remove, reconnect the cable to ensure it's got a good secure connection. But be careful, the ribbon cables can tear if not handled properly.

EDIT: ribbon cables are often socketed to the motherboard with a long latch like thing. I flat screw driver or a finger nail can be used to gently lift up the latch to free the cable from the socket. Reinstallation is the reverse process.

If the laptop is still under warranty, I recommend you have it RMAed.
 

Crocodeal

Commendable
Apr 30, 2016
6
0
1,510
0
@Barty I think I was clear enough. I do type accurately. Go troll somewhere else.

@hang-the-9 It would most likely work. I don't have a keyboard at hand now but... Isn't there a way to fix the built in keyboard of the laptop?
 

Peter Martin

Estimable
Oct 9, 2014
471
0
5,010
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i agree, going that fast with a built in kb is suspect, maybe you have worn it out.you need a professional Mechanical keyboard for what you are trying to do on a craptop with the cheapest of cheap keys.,
 

Barty1884

Admirable
Moderator
Not trolling - a laptop keyboard typically varies from a full-size and, given the phantom keys are nearby (and typing slower fixes the issue), you may well be hitting additional keys. Not like you're getting a phantom "1" or "f" when you're typing "L", you're getting "." or "O".

I'm pretty accurate myself (not to 90WPM, somewhere more in the 65-75WPM range), but that will vary depending on the keyboard you use.
For typing WPM, I'd usually hit the same number of "words", but accuracy goes out of the window. For me, it's pretty clear that my accuracy is near perfect on my full-sized mechanical KB... Less so on my cheapo office wireless membrane KB and much, much worse on my laptop.

An external keyboard won't confirm your typing ability (especially given it's most likely going to be a larger layout) but, assuming you're 100% convinced you're not hitting any other key, then it would at least help identify the issue as resting solely with the laptop keyboard.
 

Crocodeal

Commendable
Apr 30, 2016
6
0
1,510
0
So, to clear things out. All the examples above are ISOLATED. Let's see what happens if I type del a couple of times deol deol deol deol deol deol deol deol deol del deol deol deol deol del deol

I hit only 3 letters. ok, let's try dea now: deqa deqa deqa de qa deqa deq adeq adeq adeq adeq deqa deq.

So... the problem is a hardware one because I come nowhere near touching O in the first example or Q in the second one. It juwst appears randomly, oh great, I found another one: just - juwst juwst juwst juwst jst juwst juwst jwts juwts.

So I suppose I need to replace the laptops keyboard, only solution.

PS. The laptop is quite new, no way I worn it out. I think the built quality was lacking.
 

stdragon

Proper
Apr 5, 2018
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The common theme I see is that all the typos are the result of an adjacent key being registered. As though there's either a problem with the rubber membrane or the controller chip not reading the capacitance values correctly.

I would try booting off Linux (made from a bootable USB flash drive) and test again to ensure it's not software related.
 

Crocodeal

Commendable
Apr 30, 2016
6
0
1,510
0


Thanks so much, great ideqa - uhh, found another one for dea = deqa deqa deq deqa deqa deqa... DEA = DEQA DEQA DEQA DEQA. I can type idea but I have to type more slowly at around 30-40 WPM I guess idea idea idea idea and it works fine.

Anyway, I tried booting Linux Mint from an USB stick - same problem. I tried Windows 7 in virtual machine - same results... So most likely an hardware issues... anything I can do to solve it? I tear down the laptop, including the keyboard to clean the dust but it didn't help.
 

Crocodeal

Commendable
Apr 30, 2016
6
0
1,510
0
I will try the secure the cable better into the motherboard, will see if that works... I doubt it for some reason. Unfortunately it's not under warranty anymore.
 

Crocodeal

Commendable
Apr 30, 2016
6
0
1,510
0
The above solution didn't work. I have to emphasise the fact that the extra keys are typed only when 3 or more KEYS are typed.

So if I type "ru" it's fine, look: ru ru ru ru. But if I type "tru", look what happens: tryu tryu tryu tryu - an extra Y appears.
 
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