Diagnostics - Dell Inspiron 7490 P115G Service Manual

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 19. LED codes
Diagnostic light codes
2,1
2,2
2,3
2,4
2,5
2,6
2,7
2,8
3,1
3,2
3,3
3,4
3,5
3,6
3,7
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 20. Diagnostics
Purpose of diagnostic tool
Trigger
Indicator of fault
Problem description
Processor failure
System board: BIOS or ROM (Read-Only Memory) failure
No memory or RAM (Random-Access Memory) detected
Memory or RAM (Random-Access Memory) failure
Invalid memory installed
System-board or chipset error
Display failure
Power rail failure
Coin-cell battery failure
PCI, video card/chip failure
Recovery image not found
Recovery image found but invalid
Power-rail failure
System BIOS Flash incomplete
Management Engine (ME) error
M-BIST (Built-In Self-Test)
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).
Pressing M key and power button
Amber colored battery indicator LED
L-BIST (LCD Built-In Self-Test)
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.
Pressing D key and power button. Also automatically
initiated during POST. Automatically initiated during
POST
Battery indicator LED blink error code [Amber, White] =
[2,8]
Troubleshooting 77