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error HP

Error Code Power LED flashes Red three times and then white two times

Memory is installed incorrectly or is bad.

? What Causes This

Incorrect DIMM installation, faulty memory modules,

How to Fix It

  1. Reseat DIMMs; Power on the system.
  2. Replace DIMMs one at a time to isolate the faulty module.
  3. If necessary, replace third-party memory with HP memory.
  4. As a last resort, replace the system board.

Source: page 98 of the official manual

From the manual

Manual page 98 — HP error Power LED flashes Red three times and then white two times

This error code appears in:

HP Elitedesk 800 G3 Small Form Factor PC