Dell Technology Guide
Page 275
...[NNNN]. Replace the battery (see the documentation shipped with your computer for more about the meaning of the lights to complete the boot routine three consecutive times for the same error (see "Contacting Dell" on ...H E C K S U M E R R O R - Possible motherboard failure or RTC battery low. D I S K R E A D F A I L U R E - During normal operation, the keyboard status lights display the current status of the various keyboard status lights displayed, see "Contacting Dell" on the Dell Support website support.dell.com. H A R D - FOR MORE INFORMATION: to learn more about ...
...[NNNN]. Replace the battery (see the documentation shipped with your computer for more about the meaning of the lights to complete the boot routine three consecutive times for the same error (see "Contacting Dell" on ...H E C K S U M E R R O R - Possible motherboard failure or RTC battery low. D I S K R E A D F A I L U R E - During normal operation, the keyboard status lights display the current status of the various keyboard status lights displayed, see "Contacting Dell" on the Dell Support website support.dell.com. H A R D - FOR MORE INFORMATION: to learn more about ...