Keyboard partially not working

[_kR15n]

After disassembling and reassembling my laptop to clean out the dust some letters of the keyboard are not working:

left shift, num 8, num 4, t, z, f5, f8, num lock and others.

Just a loose keyboard ribbon cable or something worse?

[SenKa]

Sounds like an incorrectly attached ribbon. You may have tore the ribbon during disassembly (we all have, no shame in it).

 

Break the laptop back down, re-seat the keyboard connector, and try again. See what changes. If it is still bad, it's time for a new keyboard.

[_kR15n]

On 6/22/2019 at 4:18 AM, SenpaiKaplan said:

Sounds like an incorrectly attached ribbon. You may have tore the ribbon during disassembly (we all have, no shame in it).

 

Break the laptop back down, re-seat the keyboard connector, and try again. See what changes. If it is still bad, it's time for a new keyboard.

Update:

Reattached the ribbon cable and it still does not respond, also i have checked for damage on the ribbon but there doesn't seem to be any. Currently it seems like a completely regular working keyboard which just decided to stop working on some places.

As the image shows the affected buttons are:

F3, F7, Backspace, Tab, Caps Lock, LShift, Num Lock, Num 4, Num 8, T, Z (forgot to test the spacebar but it works, also couldn't test PgUp, PgDn, Home and End because Num Lock does not work, RShift also works)

 

[SenKa]

9 minutes ago, _kR15n said:

Update:

Reattached the ribbon cable and it still does not respond, also i have checked for damage on the ribbon but there doesn't seem to be any. Currently it seems like a completely regular working keyboard which just decided to stop working on some places.

As the image shows the affected buttons are:

F3, F7, Backspace, Tab, Caps Lock, LShift, Num Lock, Num 4, Num 8, T, Z (forgot to test the spacebar but it works, also couldn't test PgUp, PgDn, Home and End because Num Lock does not work, RShift also works)

A torn ribbon cable is often very difficult to see, you cannot know if it is torn without checking continuity via a multimeter.

 

I still suspect a torn ribbon.