half of keyboard stopped working

Hi all,

so last week when I booted my laptop it when to diagnostic test and gave me the no backlight cable error, which I thought is fine because I have had to replace the original keyboard already to one without a backlight, however by the end of the week half of the keys stopped working so I got a new keyboard but this has the same keys not working. any idea what the problem is and how it can be fixed?

Thanks in advance