Service Manual

Table 20. LED codes
Diagnostic light codes Problem description
1,1 TPM detection failure
1,2 Unrecoverable SPI flash failure
1,5 i-Fuse failure
1,6 EC internal failure
2,1 Processor failure
2,2 System board: BIOS or ROM (Read-Only
Memory) failure
2,3 No memory or RAM (Random-Access Memory)
detected
2,4 Memory or RAM (Random-Access Memory)
failure
2,5 Invalid memory installed
2,6 System board or chipset error
2,7 Display failure - SBIOS message
2,8 Display failure - EC detection of power rail
failure
3,1 Coin-cell battery failure
3,2 PCI, video card/chip failure
3,3 BIOS Recovery Image not found
3,4 Recovery image found but invalid
3,5 Power-rail failure
3,6 System BIOS Flash incomplete
3,7 Management Engine (ME) error
System board built-in self-test (M-BIST)
About this task
M-BIST is a built-in self-test diagnostics tool that improves the accuracy of diagnostics of embedded controller (EC) failures in
the system board. M-BIST must be manually initiated before POST and can also run on a dead system .
To invoke the system board built-in self-test (M-BIST), perform the following steps:
1. Press and hold both the M key and the power button to initiate M-BIST.
2. The battery-status light illuminates in amber when there is a system board failure.
3. Replace the system board to fix the issue.
NOTE: The battery status LED does not illuminate when the system board is functioning properly.
Recovering the operating system
When your computer is unable to boot to the operating system even after repeated attempts, it automatically starts Dell
SupportAssist OS Recovery.
Dell SupportAssist OS Recovery is a standalone tool that is preinstalled in all Dell computers installed with Windows 10 operating
system. It consists of tools to diagnose and troubleshoot issues that may occur before your computer boots to the operating
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Troubleshooting