If your Pi cannot detect the EDID and do the the right thing you must set the /boot/config.txt
If your screen looks like this
It is not broken - what is happening is you are sending 640x480 data to the monitor but since it does not have a scaler, and the display is 800x480, the remaining 160 pixels are 'not drawn' - you must set the resolution of your computer to 800x480 to get all of the pixels used! For raspberry pi, check the Config page for the correct config.txt setup for 800x480
Use raspi-config to force audio out the 3.5mm audio jack (rather than HDMI or auto).
If you still have issues, edit /boot/config.txt and add or un-comment this line: