Thanks for the quick reply!
I start up my device and get the rockbox bootloader process which seems fine and then the messy splash screen comes up and nothing seems to respond.
After trying to restart a couple of times I got to the main menu, but once I try to play a file, the screen gets messed up again and doesn't refresh anymore (although music plays), and since I'm new to rockbox I can't navigate it.
Further restarts are stuck in the splash screen again.
The messed up splash and menu screens seem to have kind of horizontal noise in the form of straight lines scrambling it and it's also somewhat rotated to the left (so it reads "ockbox r").