Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

[dood]

Title pretty much says it all. Got a laptop in that "won't boot" - found that it booted up fine, but wouldn't respond to any input from the keyboard... and that the keys were particularly sticky.

Cleaned everything up best I can, but I ruled the keyboard a loss, and ordered a replacement from the 'bay. This is a brand-new, genuine Dell part... Arrived today and I popped it in, only to find that the keyboard is still unresponsive. I'm guessing maybe a keyboard fuse blew (do they still exist)? Apart from going over the motherboard with a fine-tooth comb, is there anything specific I can check?

It really seemed like the keyboard collected most of the spillage, though there was enough underneath it that it was stuck fast to the plastic when I tried to remove it.

[lezsimply]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

Does capslock led lit when pressed? And also you can check 3.3v on pin1 of CON1?

[dj_ricoh]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

i got 2 fujitsu (identical) with the same problem.
let be tell you something maybe it will give you a hint.
one its working with usb keyboard and one NO.
both of the notebook boots up if they got OS on HDD.
KBC will be swap soon in the one that its not responding with usb KB

[dood]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

Does capslock led lit when pressed? And also you can check 3.3v on pin1 of CON1?

No capslock LED when pressed. 3.3v is present on pin1 of CON1.

i got 2 fujitsu (identical) with the same problem.
let be tell you something maybe it will give you a hint.
one its working with usb keyboard and one NO.
both of the notebook boots up if they got OS on HDD.
KBC will be swap soon in the one that its not responding with usb KB

This one boots up and runs fine with a USB keyboard.

[lezsimply]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

I assume you have schematic, if not I have attached one.

I think it has something to do with KB_DET# pin no.106 of SIO ITE8518E page30. I think its for detection and 3.3v should be present. please correct me guys if I'm wrong thanks Also check CAP_LED pin27 of CON1, I think 5v should be there. see page.36

I cannot really confirm because I don't have datasheet for it, cannot seem to find using google or its just me

[spidey]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

change EC, if keyboard shorted by liquid may also damaged EC.

[dood]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

Sorry, what do you mean by EC?

[spidey]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

embedded controller.

[Francisco.s]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

No capslock LED when pressed. 3.3v is present on pin1 of CON1.

Pin1 of CON1 KB_DET#, is active when low level (#), so if you have 3.3v, is probably that keyboard is not detected.

That signal, goes to pin 106 of embedded controller (U9).

Try to force KB_DET# to low level, and post results.

[dood]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

Pin1 of CON1 KB_DET#, is active when low level (#), so if you have 3.3v, is probably that keyboard is not detected.

That signal, goes to pin 106 of embedded controller (U9).

Try to force KB_DET# to low level, and post results.

Force it to a low level by grounding it out?

[Francisco.s]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

Force it to a low level by grounding it out?

Yes, but better, if you do it through a 1 kohm resistor.

[dood]

Re: Dell Inspiron N7110 keyboard spill - replacement keyboard still unresponsive

So, I tore into this further today... Pulled the motherboard, went over it with a fine-toothed comb just to make sure I didn't miss any spillage. There were a few small spots, but nothing serious.

Put it all back together, still nothing. Then, as I sat here looking at it.... it dawned on me. Maybe my dumb ass had the cable upside down. Sure, the cable LOOKED right the way it was... but what does it hurt to try? Flipped the ribbon cable over, and hey presto, we have a working keyboard.

I really can't believe I've been frustrated by this for over a week, and all it took was flipping the cable over. To be fair, though, it really doesn't look right installed this way. The keyboard doesn't sit flat anymore, and I will have to carefully crease the cable to make it work.