Service Manual

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 17. 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 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
3,7 Management Engine (ME) error
Camera status light: Indicates whether the camera is in use.
• Solid white — Camera is in use.
• Off — Camera is not in use.
Caps Lock status light: Indicates whether Caps Lock is enabled or disabled.
• Solid white — Caps Lock enabled.
• Off — Caps Lock disabled.
Diagnostics
Table 18. Diagnostics
M-BIST (Built-In Self-Test) L-BIST (LCD Built-In Self-Test)
Purpose of diagnostic tool Evaluates the health of the system
board, allowing users to assess
whether the system board is the
source of the problem if there is no
power, no video output, or if the
system does not start-up properly
(no POST).
Checks if the system board is supplying power to the
LCD display by performing an LCD Power Rail test, which
allows for isolation of "No Video" symptom to Mainboard,
LCD or Cable.
Trigger Pressing M key and power button Pressing D key and power button. Also automatically
initiated during POST. Automatically initiated during
POST
Indicator of fault Amber colored battery indicator LED Battery indicator LED blink error code [Amber, White] =
[2,8]
Repair instruction Indicates a problem with the system
board.
Indicates a problem with the system board.
Troubleshooting 63