SN850 won't POST, LED pulses blue

I have a 1TB SN850, purchased new in November 2022. It has never given a hint of a problem. It is installed in an ASUS ProArt Creator X670E WiFi motherboard, although it has also been used in others. I use it with Linux and I do not have Windows.

Last week I left on a trip and I turned my PC off. It had been running continuously for months, again without a hint of a problem. I returned after being gone for 5 days, turned on the PC, and it either can’t POST, or it does POST straight to the BIOS, showing no storage devices.

With the PC powered on, the SN850 LED throbs blue.

Things I have tried that did not resolve the issue:

  1. Replaced the SN850 with a Samsung SSD. PC works perfectly. So that rules out the platform, mostly.
  2. Updated motherboard to latest BIOS. No improvement.
  3. Removed CMOS battery, shorted pins to clear CMOS. No change.
  4. Moved the SN850 to other slots. No change.
  5. Waited a long time, in case the SSD is doing some kind of housekeeping. Futile, so far.

I can’t resolve this with WD Dashboard because the machine can’t POST. What does the flashing LED signify, and what are some possible causes of these symptoms? Why would it emerge after a short time powered off?

I put this device in another PC where it does manage to POST. The WD Dashboard can see it, but offers no firmware update. The FW is 615000WD. 615400WD is posted on WD’s site but it seems there are no upgrade paths from 615000WD to 615400WD. The release file says you may upgrade from 615300WD or 615100WD but neither of those are available.

Your issue may be related to firmware or hardware failure. First, connect the SSD to a different PC where it’s detected and back up any important data. Since the firmware cannot be updated directly, contact WD Support for guidance on firmware compatibility or a manual update path.

Use WD Dashboard to run diagnostics and consider performing a secure erase if data recovery is not needed. If the problem persists, it may indicate a hardware fault, and initiating a warranty claim or replacement could be necessary.