While upgrading the RAM from 2x8gb to 4x8gb we are running into a RAM boot error issue.

 The laptop will boot the first time perfectly fine; however, each time thereafter it will display that boot error via the LED status lights.  We have troubleshot this issue pretty extensively with multiple 7520’s using both the OEM DELL RAM as well as aftermarket RAM.  The issue only occurs when there are 4 RAM slots in use.  If there are only 2 RAM slots in use, regardless of which 2 and regardless of which brand RAM, the issue does not occur.

 With this issue occurring with every 7520 we have encountered we have believed it to be Firmware related; however, there are no recent firmware updates via Dell. We have not experienced this issue with the 7510’s and there is very little difference with the 7520’s.  Our temporary solution has been to purchase and use 2x16gb.

 If anyone has experienced a similar issue, or has a resolution,  please let us know.