Passwort root

[u.lorenz@er-dresden.de 0]

I installed Tinker_Edge_T-Mendel-Eagle-V3.0.7-20210610. When running sudo nano I get an error >>> /etc/sudoers: syntax error near line 28 <<<.
Does anyone know root's password? (I've already tried 'mendel', that's not it!)

[tooz 54]

hello @u.lorenz@er-dresden.de, 

both the username/ pw are: mendel

looks like the sudo isn't functioning and perhaps reflashing the board would be the most efficient way to fix it.