Dell Mobile Precision 7750

Diagnostics

Does the System Board work (M-BIST)?

  • Press and hold M and power to run. On system board failure, the battery status LED is solid amber. It’s not on if the board passes.

Is the LCD powered by the system board (L-BIST)?

  • Runs automatically during POST. On no power to LCD (the screen), the battery status LED flashes amber twice (2) and white eight (8) times.

Does the display panel work (LCD-BIST)?

  • Press and hold M and power, then release M and power when POST starts. The display should cycle through colors and reboot. Look for graphical anomalies.

System diagnostic lights

  • Battery-status light: power and battery-charge status. Blinks amber and white, along with beeps for failures.
  • Solid white when the power adapter is connected and the battery > 5%.
  • Amber when running on battery, and the battery < 5%.
  • Off when the power adapter is connected, the battery is fully charged, the battery is> 5%, or the computer is in sleep, hibernation, or off.

System diagnostic light codes

Example

A diagnostic light code of [2,3] means the power and battery-status light blinks amber twice (2), then pauses, then blinks white three times (3), then pauses, in a loop until the computer is turned off.

Diagnostic light codes Problem description Recommended Solution
1,1 TPM Detection Failure Replace System Board
1,2 Unrecoverable SPI Flash Failure Replace System Board
1, 5 EC unable to program i-Fuse Replace System Board
1, 6 Generic catch-all for ungraceful EC code flow errors Disconnect all power source (AC, battery, coin cell) and drain flea power by pressing & holding down power button
2,1 CPU failure Run the Intel CPU diagnostics tools. If problem persists, replace the system board
2,2 Motherboard covers BIOS corruption or ROM error Flash latest BIOS version. If problem persists, replace the system board
2,3 No Memory/RAM detected Confirm that the memory module is installed properly. If problem persists, replace the memory module
2,4 Memory/RAM Failure Reset the memory module. If problem persists, replace the memory module
2,5 Invalid memory installed Reset the memory module. If problem persists, replace the memory module
2,6 Motherboard/Chipset Error Flash latest BIOS version. If problem persists, replace the system board
2,7 LCD failure - SBIOS message Flash latest BIOS version. If problem persists, replace the LCD module
2,8 LCD failure - EC detection of power rail failure Replace the system board
3,1 CMOS battery failure Reset the CMOS battery connection. If problem persists, replace the RTC battery
3,2 PCI of Video card/chip failure Replace the system board
3,3 BIOS Recovery Image not found Flash latest BIOS version. If problem persists, replace the system board
3,4 Recovery Image found but invalid Flash latest BIOS version. If problem persists, replace the system board
3,5 EC ran into power sequencing failure Replace the system board
3,6 Flash corruption detected by SBIOS Replace the system board
3,7 Timeout waiting on ME to reply to HECI message Replace the system board

Info from link.