Keyboard replacement not working properly

Hello,

I've replaced the keyboard and trackpad on the laptop and some of the keys work but spit out random letters and numbers but the trackpad works, no sound is playing either. Does anyone have experience with replacing keyboards on laptops? I'm sure all the cable wires have been connected correctly.

LAPTOP: Samsung NP300E5C

This is what I bought as a replacement. https://www.ebay.co.uk/itm/223667685746

Any advice?

Thanks

Javed