On occasion, my Precision 390 will lock up on boot at the BIOS screen (see the photo below).  It doesn't happen all the time though.  I can go several days without it happening or several days in a row that it will happen.  It was a couple weeks out of the box before I first noticed the issue.  I can restart the machine and sometimes it boots normally.  Other times it will lock up again.  I did a search here and followed some of the advice like checking the internal connections. 

 

I had found a thread after the first time this happened that sometimes there is a conflict between memory card readers and the BIOS on other machines (can't find that thread now).  The fix was to upgrade the BIOS.  I already have the latest BIOS.  I removed the internal card reader because the monitor came with one and I am using that one.  For now, if the machine freezes during boot, I turn off the monitor and restart.  So far I haven't gotten any lockups with it off but turning off the monitor shouldn't cause the integrated reader to turn off as well...  At this point, I'm not really sure what else to try before calling tech support.  Anyone have any ideas?