I've investigated some more. Somehow it seems like the driver is missing.
First I stopped the server.
sudo /etc/init.d/LCDd stop

Then I tried starting LCDd with the Matrix Orbital driver.
fredrik@HTPC:~$ sudo LCDd -d MtxOrb
MtxOrb: Speed must be 1200, 2400, 9600 or 19200. Using default value of ...

Raquel wrote:If you please close all applications that communicate with the display. Power up the display (plug it in). Does it show the startup screen properly?

Yes it does.

I've checked the baud rate, and it's set to 19200. I've installed the latest debian package of MythTV, and apparently it installed lcdproc automatically. Everything seems to be in order, but it still shows nonsense characters.

Now it's running MythTV, version 0.20-svn20070122-0.0ubuntu6~edgy1 and ...

Hi!

I've built an HTPC based on a Via Epia. I tried connecting a HD44780 compatible display to the parallel port, but the signal current from the Epia is just 3.3V, which isn't enough.

To solve this, I bought a Matrix Orbital MX6 without buttons. But I can't get it to show anything more than ...