Hello...first time poster, long time watcher...

I have a Precision T5810 with 32GB of RAM.  I purchased another 32, but the machine won't take it.  If I remove the original 32 (in the white tabs), and replace it with the new 32 (also in the same white tabs), it boots up like normal.  But 'adding' to what's already there produces no POST, and a flashing power button light that appears to be blinking 3-5.  The stickers on both sets of RAM are the same (I know, still could be wrong).  But it basically doesn't like anything in that second set of slots (black tabs).  If it didn't like one set over the other I'd chalk it up to the wrong RAM.  But it takes either/or...but not both.  Ideas?    GO!