M-BIST
M-BIST (Built In Self-Test) diagnostics tool, featuring improved accuracy in system board failures.
NOTE: M-BIST can be manually initiated before POST (Power On Self Test).
How to run M-BIST
NOTE: M-BIST must be initiated on the system from a power-off state either connected to AC power or with battery
only.
1. Press and hold both the M key on the keyboard and the power button to initiate M-BIST.
2. With both the M key and the power button held down, the battery indicator LED may exhibit two states:
a. OFF: No fault detected with the system board
b. AMBER: Indicates a problem with the system board
System diagnostic lights
Battery-status light
Indicates the power and battery-charge status.
Solid white — Power adapter is connected and the battery has more than 5 percent charge.
Amber — Computer is running on battery and the battery has less than 5 percent charge.
Off
• Power adapter is connected and the battery is fully charged.
• Computer is running on battery and the battery has more than 5 percent charge.
• Computer is in sleep state, hibernation, or turned off.
The power and battery-status light blinks amber along with beep codes indicating failures.
For example, the power and battery-status light blinks amber two times followed by a pause, and then blinks white three times followed by
a pause. This 2,3 pattern continues until the computer is turned off indicating no memory or RAM is detected.
The following table shows different power and battery-status light patterns and associated problems.
Table 3. LED codes
Diagnostic light codes Problem description
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
2,8 LCD power rail failure. Replace system board
3,1 Coin-cell battery failure
3,2 PCI, video card/chip failure
3,3 Recovery image not found
3,4 Recovery image found but invalid
3,5 Power-rail failure
3,6 System BIOS Flash incomplete
Troubleshooting 55