Quit X, and at the command line type:
startx &>/tmp/Xerrors <--this syntax assumes you're using bash. For csh, transpose the & and >
This will start X, but will also create a file in /tmp called Xerrors, and write the standard output and standard error of the startx command to that file. Quit X again and type:
to view the file. You can use the up/down arrows and pg up/ pg down keys to navigate. Look for any errors messages, especially those relating to fonts and font directories, and post your findings here.