Macbook a1181 problem command key that also operates comma key

[sorry for the translation with google translate]

Hi everyone, I'm experiencing a problem that I can't find a solution on the net.

I have macbook, a mid 2009, with osx El Capitan installed that has the keyboard with this problem:

if I press the "command" key on the left, the comma key is also activated, if I press the right command key the right arrow is operated, so it is impossible for me to use for normal commands like close window, copy and paste. If I press instead the comma or right arrow key works normally.

I did both the PRAM reset and the NVRAM and SMC reset.

I tried starting it in the command line and the problem also appears in the Shell.

I tried with other users and the problem persists.

I installed the system, El Capitan, from scratch but nothing.

I removed the keys but nothing is abnormal.

With external keyboard it works correctly.

I tried the KyeMap program but nothing, the result does not change.

What can it be for you?

Has anyone ever experienced such behavior?

Is there any command line solution I can apply?

thanks in advance for the help.