What to Replace, Screen Digitizer or LCD Display?

Hello,

A few months ago my iPod nano 7th generation went through the wash... I took it out and it still played music. The only issue is that the display only flashed on for a split second when I touched the screen (the touch feature was still working) or pressed one of the external buttons. So it was very hard to use!

I resolved to try and fix the iPod myself (after asking around at repair shops that asked ridiculous prices), but I'm not sure if I should replace the Screen Digitizer or the Display itself? I'm very new to this!

Thanks in advance for your help, any is appreciated.

Liam