K5M - garbled display/bricked

I've got a K5M that has a problem with the display - then first powered up it shows the K5M splash screen, but when it finished booting up, the display is garbled - showing ??? marks across the screen. At this point, it's locked up and none of the functions/buttons seem to work. 
 

 I've checked the PSU voltages and they are all good. I also opened it up and reseated all connectors. At this point it's dead in the water...
 

 Any suggestions on how to fix it?
 

 Thanks
 Kirk