You say you can get to a console. Is that from the Mandriva login screen? Are any messages displayed? Can you login as root from the console? (I don't use Mandriva so don't know what their protocols are)
Is this on a fresh (recent) install?
Also would you please expand on the installation, such as version and what selections you made (which desktop), what hardware your system uses (particularly the graphics card), and any other related information you can provide.
If possible can you also include the contents of dmesg.