Error: CONF_DONE failed to go high in device 1.

Hi,

one thing I got wrong (I hooked up my scope to check) is the CONF_DONE pin which is definitely low from power up.

If the nConfig is high, there is nothing on your circuit triggering a reconfiguration (e.g. the EPCS4). It definitely seems like the configuration data are not matching the device as the pin is raised only for fault free configuration data received and configuration being completed... Using a *.sof not targeting the device detected ends in "Can't configure device. Expected JTAG ID code... for device 1, but found JTAG ID code ...".

This seems to eliminate the "false target device" option.

One last: Which version of QuartusII are you using for generation of the *.sof? Have you tried to compile with "generated compressed bitstream" disabled? (There was one QuartusII release that failed generation of compressed bitstreams...)

HTH

I can offer you to try your's sof on my board to countercheck if the file or the HW is causing the trouble anyhow.