Asus UX510U issue with 8 keys on the Keyboard

[JG2018]

Hello everyone,

I have an issue with an Asus UX510UWK Rev 2.0. The issue is that there are 8 letters that are not functioning at all, which are: 6, 7, y, u, h, j, n and m keys.

With an external keyboard it works perfectly. Boot on an Ubuntu bootable key, and have exact same issue (so i can assume it's not a software related issue)?

Already test another keyboard and i have the exact same issue (so not a keyboard issue). Cleaned the Keyboard FPC with IPA, changed nothing.

Checked closely the board, no water damage and nothing seems to be damaged.

Took off board the ENE IC (I/O), solder it back on the board, exact same issue.

I'm stuck..

Does anyone have any idea what can i test or check next?

Thanks in advance for your good advices.

Regards

[KvnTM]

Have you checked continuity for all lines from EC to Keyboard flex? Maybe there's a broken/bent pin in the ffc connector.

[JG2018]

What do you mean by EC?

[KvnTM]

Originally Posted by JG2018

What do you mean by EC?

ENE IC (I/O) = EC/KBC/Super IO

The keyboard traces should go into it.

[JG2018]

Have token off board ENE IC, resolder back on board, but still exact same issue. All the pins of ENE IC seems to be ok (not broken or particularly bend) and did diode mode on each pins of ENE IC, all give values (have few line, maybe 6-7 which has continuity with ground but as i don't have schematics, i don't know if it's normal or not and therefore if it's the cause of the issue here). What do you think? Thanks.

[JG2018]

Here is my diode mode readings from pin right to left. I have weird value on pin 1 and 4 but don't know if it's normal? All the other pins gave .608 (have 1 GND on pin 6 and 2 OL on pin 2 and 3).

[KvnTM]

Originally Posted by JG2018

Here is my diode mode readings from pin right to left. I have weird value on pin 1 and 4 but don't know if it's normal? All the other pins gave .608 (have 1 GND on pin 6 and 2 OL on pin 2 and 3).

Please don't use diode mode for such measurements. Use resistance mode instead.

It would help a ton if you upload a close up high quality photo of the keyboard connector where I can see the tracks. Sadly I can't find a schematic for that laptop...
My bet is still a bent/broken pin in the connector. Can you measure each pin from connector to the keyboard flex itself?

One thing to try: Get a thin piece of tape and apply it to the solid plastic flap which goes into the connector. Just to make the cable a little bit thicker. Maybe there's just a connection problem inside the connector. Who knows.

I'm talking about the little rigid plastic end on the ffc (blue on the example picture below). Hard to explain.

[JG2018]

Ok will try resistance mode measurments also and will let you know (you mean put in 200 Ohms on multimeter mode with red on ground and black on pin, correct?)

I've test continuity of each pin of Keyboard connector to pins of ENE IC and have continuity for each pins but not for the fourth first pins (so the 2 different diode mode measumrents + 2 OL).

I can try to make the flex thicker but it does exactly the same with a brand new keyboard.

Please let me know your thinking

[KvnTM]

Originally Posted by JG2018

Ok will try resistance mode measurments also and will let you know (you mean put in 200 Ohms on multimeter mode with red on ground and black on pin, correct?)

No! Put one probe on one pin of the connector and one probe on the corresponding pin of the ene chip. The polarity doesn't matter in this case.

Originally Posted by JG2018

I've test continuity of each pin of Keyboard connector to pins of ENE IC and have continuity for each pins but not for the fourth first pins (so the 2 different diode mode measumrents + 2 OL).

I assume the first 4 pins are supply pins. Probably 2 gnd and 2 vcc.
Two of those should be 0 Ohm to gnd.
Please upload good photos of it.

Originally Posted by JG2018

I can try to make the flex thicker but it does exactly the same with a brand new keyboard.

Please let me know your thinking

A new keyboard won't replace the connector my friend. Theres probably or most likely a problem with the connector. Do you have a microscope? Take a look inside the connector and make sure all pins look alright. This also works with a flashlight and good eyes. The pin pitch isn't that small on those.

[JG2018]

Ok will upload a picture of Keyboard connector so you can see the traces. Pin 1 and 4 have traces while 2 and 3 seems to be unconnected pads.

Already cleaned inside of connector with a microscope, everything seems clear inside.

[JG2018]

Here the pictures of connector

[JG2018]

Any idea?

[jasko_jacker]

Check connection with multimeter from the connector to EC but I think it is necessary to try to reprogram the EC

[KvnTM]

Why does the board look so dirty or burned?
Anyways... Just do what I & jasko_jacker told you. Check for continuity from each pin on the connector to EC. Measure directly on the EC pins if possible.

Just put one probe on one pin of the connector and carefully swipe across the pins on the EC until your meter beeps. Be really careful to not bend any pins on the EC! Don't apply too much pressure with your probe. You've been warned..

I don't think that it will be necessary to reprogram the EC since everything else works fine and it would be odd if some keys won't work because of a messed up firmware..

[JG2018]

Originally Posted by jasko_jacker

Check connection with multimeter from the connector to EC but I think it is necessary to try to reprogram the EC

How can i do that sir?

Already checked continuity from each pin of keyboard connector to ENE IC. Have continuity for each pin but not for the first 4 on the top of first picture.

[JG2018]

Originally Posted by JG2018

How can i do that sir?

Already checked continuity from each pin of keyboard connector to ENE IC. Have continuity for each pin but not for the first 4 on the top of first picture.

I means those 4 (the 2 in the middle i think they are not connected, so it's OL)

[JG2018]

Originally Posted by KvnTM

Why does the board look so dirty or burned?
Anyways... Just do what I & jasko_jacker told you. Check for continuity from each pin on the connector to EC. Measure directly on the EC pins if possible.

Just put one probe on one pin of the connector and carefully swipe across the pins on the EC until your meter beeps. Be really careful to not bend any pins on the EC! Don't apply too much pressure with your probe. You've been warned..

I don't think that it will be necessary to reprogram the EC since everything else works fine and it would be odd if some keys won't work because of a messed up firmware..

Already did that, as told in previous post Have continuity for each pin of keyboard connector, just not the 4 i put in last picture. 2 in the middle are OL (unconnected i think)

[KvnTM]

Originally Posted by JG2018

Already did that, as told in previous post Have continuity for each pin of keyboard connector, just not the 4 i put in last picture. 2 in the middle are OL (unconnected i think)

Can you trace where they go ? Sadly there is no schematic for that board..

[JG2018]

Originally Posted by KvnTM

Can you trace where they go ? Sadly there is no schematic for that board..

You mean the 4 pins not connected to ENE IC? Not really, can double check it but...

[JG2018]

Found this on Vinafix but wasn't able to open them