If you replaced the keyboard and the same exact keys are still not working then you most likely have a system board issue.
But check basic things and make sure before turning to any chip level operation that did you insert the cable properly and is your zip connector or header of keypad is good or broken from anywhere?
Some of my known people who connected with the laptop computer hardware repairing filed but they don't done any chip level work on laptop so they use to send me the faulty laptop for repair in which they feel a chip level issue they do only diagnose and fix only software and common hardware level problem like installation of software, OS and part replacing work replace hard drive, ODD, LCD, Keypad, Touch-pad, Hinge and main board but replacing main board is too much costly.
Some
time problem can't get fix after just replacing the part that they
think is a faulty spare because they do repair on the basic diagnostic
way if keypad not working ( problem can be some keys not working or
functioning properly, keypad died not detected at all ) after checked
some basic thing like OS issue driver and finally replaces the keypad as
usual we all have to do.
But
if problem couldn't get fix then its means problem is not a normal
issue that will need a chip level operation so as usual they forward me
this case. When they come to me most likely they said ''I have replaced
the keyboard on this laptop 2, 3, 5 times but sill keypad not working.”
These same letters stop working after a while. Replacing the keyboard
worked before'' also most of the time same thing happened with mouse
touch-pad.
Before
I going to tell how can easily repairer this kind of case..I just want
to remained you a basic block diagram of laptop motherboard.
Every
laptop notebook manufacture uses a different type keypad model and
their header for their different laptops models. And there header size
and their pin datasheet may not be same. so
before wasting your time to get datasheet and any other solution to fix
the problem to searching on Google just re-soled the I/O chip and pull
up resistor pack capacitor pack or simple SMD resistor which have
connected with keypad connector and direct with I/O chip because today
laptop manufactures use the I/O chip which have in built EC controller.
You can use hot air blower or a micro iron for re-soldering process… mostly pull up resistor and capacitors has solder nearby the keypad connector or header.
You can use hot air blower or a micro iron for re-soldering process… mostly pull up resistor and capacitors has solder nearby the keypad connector or header.
Pay little care if you have not familiar with SMD components.
If after re-soldering can fix you problem then you must have to change the EC or I/O chip
