!
error HP

Error Code Blink = 4

The embedded controller has timed out waiting for BIOS to return from graphics initialization, possibly indicating a missing or faulty MXM module.

? What Causes This

Graphics driver configuration did not complete successfully in the expected time frame.

How to Fix It

If an MXM module is used, trying a different module may resolve. Otherwise, replace the system board.

Source: page 84 of the official manual

From the manual

Manual page 84 — HP error Blink = 4

This error code appears in:

HP Elitebook 840 G5 Notebook PC