Frequently Asked Question
Why will an Ultrastar SATA drive not spin up in my desktop or enclosure?
ACE SUPPORT · WD
Some enterprise SATA variants support Power Disable on power-connector pin 3. A host that supplies 3.3 V to that pin can hold such a drive in reset. This is model-specific, so confirm the complete part number and host compatibility before assuming the drive has failed.
Applies to
Ultrastar SATA HDD variants with documented Power Disable support. Ultrastar SAS drives, legacy pin-3 variants and ordinary external USB products require their own compatibility checks.
Before you begin
Do not tape contacts, cut wires, remove pins or use an unverified power adapter as a customer workaround. Never initialise a drive with existing data just to test whether a power issue has cleared.
Work through these checks
- Record the complete model and part number from the label and check its official product manual or specification. A shared capacity or family name does not mean all variants have identical power-pin behaviour.
- Confirm that the drive interface matches the controller or enclosure. A SAS model requires a supported SAS host; a SATA-only adapter is not an interchangeable solution. Check the host's supported sector formats and drive requirements as well.
- Have the system builder or administrator check the power supply, backplane and enclosure documentation for SATA Power Disable support. WD's technology brief explains why a permanently high pin 3 can prevent the relevant SATA drive from spinning.
- Use only an approved compatible power connection, backplane or enclosure selected by the system builder for that exact combination. Keep power off before any permitted hardware change and follow the equipment's handling procedure.
- If the drive still does not spin or is not identified through a confirmed compatible host, arrange a hardware assessment. If it previously held essential data, stop repeated power cycling and preserve the original drive and connections for the Specialist.
Confirm the result
Verify that the host reports the correct model and full capacity through the supported connection. For a drive containing data, check readability and backup before any write or diagnostic workload. Detection does not prove long-term health.
When to contact us
Provide our Support Specialist the exact drive part number, interface, enclosure or backplane model and power-supply details. This is especially important when buying an enterprise drive for a consumer desktop.
Updated 261105