2 Bronze

XPS 15 9550 won't boot - power light turns on (white) no beep or light codes, no POST


Was experiencing general issues with my windows profile after windows updates last patch Tuesday so I initiated a system restore and let it run today.  After completion laptop turned off (instead of rebooting?)

  1. Pressing the power button: Power button turns white (on) for ~30 seconds, then laptop turns off (indicated by power button light)
    1. no fans
    2. no screen (back-light or otherwise)
    3. no POST codes - beep codes or light codes.  
    4. no other visible activity
  2. During that period nothing else happens, unless I press the power button again. If I do this
    1. The fans spin up momentarily
    2. The system then powers off (as indicated by the white power light)

I've tried:

  • Disconnect power/battery and hold power button (60 seconds)
  • Power system on with just battery
  • Power system on with just wall power
  • Remove mSATA HD and repeat the above
  • Disconnect video connector and repeat above
  • Remove mPCI WiFi module and repeat above
  • Completely disassemble and remove CMOS battery (tested at 3.1 VDC) for 60 seconds, reassemble and repeat above

All with no change in behavior

  • I am able to get a light code 2 Amber / 3 White if I remove the RAM module (as expected)
  • D + PWR diagnostics cycle successfully through a range of colors then nothing

Laptop is 2 months out of warranty.  Any help debugging the issue is appreciated!

XPS 15 9550 September 2016

Other notes:

  • UEFI Secure Boot was enabled
  • HD was bitlocker encrypted in Windows 10
  • HD is currently removed and has not changed behavior

Thanks so much!

This Reddit article appears to be similar:

Here's the XPS 15 9550 Service Manual:

And the blink codes:

1 Reply
dell-robert p
7 Gold

RE: XPS 15 9550 won't boot - power light turns on (white) no beep or light codes, no POST

Hi Christopherjeffry,

Thanks for posting.

Apologies that your system is not working as you expected.

Unfortunately from the research I can find, it would appear that the motherboard has failed.  You can contact Dell's Out of Warranty department for information on costs of parts and repairs, or you could consult with a local computer repair shop.

0 Kudos