Okay,
So here’s the whole story. I’m making a MB SIDv2. I previously had a 2x20 LCD screen and everything was working fine (in 8-bit mode according to my wiring)
Then an accident happened and the damn thing was smashed.
So I bought a new 2x24 screen but in debuging the setup (mostly a backlight issue) I found the 4-bit wiring diagram for V2. I did not include those 4 connections on my LCD so it would be 4-bit. But now the LCD works but is no longer displaying the SID screen. It actually displays text saying it’s a “LCD Screen”
What kind of message is this? Why was my original LCD working on 8 bit?
What PCB? Wilba’s?
The 8bit driver on a v2 is not standard, and if you plugged in a 4 bit LCD with the 8bit driver, it won’t behave… sounds like the corrupted message that arrived triggered a factory message… I wouldn’t do that again, lord knows what you could be doing to the lcd 
So, either wire it up for 8bit (i would) or change the software to a 4bit driver and re-upload.
I see, so it must be configured for 4bit? So it’s 8 bit automatically?
4685’s are 4 bit automatically, unless you configure them to use the user lcd driver, and wilba included a user lcd driver that does 8bit using spare pins. I got the impression you were using it before
You didn’t answer my question… Now I’ll add to it. Which hex file did you upload?
The standard 6851 hex file. I don’t have slaves, so I’d like to activate the 8bit I suppose. No, not Wilbas, just a regular one.
It’s a stereo SID setup however. Should I go with 4bit or 8bit? And what must I configure to get these options?
Well if you can make the LCD work in 4bit mode, I’d say do that, simply because it’s the default and easier 
You just need to disconnect the extra four wires from your LCD so it’s wired up like the 4bit PDF you found.