To explain this takes a trip and story about how keyboards work. Rather than do that the most common fix is to replace the keyboard. For your info, it's called a scan matrix failure.
I use laptop dell LATITUDE E4300 and after I open it for 5min, the key " 4, R, F, V, 5, T, G, & B" are locked, even I did nothing with it. can you help me? I noticed that when I turn it on there is a light of locked #9 on.
if you need more information, please feel free to send me an email. Thank in advance for your help.