critical HP

Error Code Red LED 10 blinks every second followed by a 2 second pause

There is an issue with expansion cards. This code highlights that something attached to the system board is malfunctioning.

? What Causes This

Problematic device such as additional graphics card, soundboard, or add-on memory modules not configured correctly might cause this error. Hardware issues like incorrect insertion of RAM can produce similar symptoms.

✓ How to Fix It

Carefully check and remove or reseat all installed cards (including onboard options).
Isolate each component by removing them one-by-one to find the faulted part.
Reconnect components in working order after identifying and handling faulty ones, typically involving replacement with known good units.

Source: page 4 of the official manual

From the manual

Manual page 4 — HP error Red LED 10 blinks every second followed by a 2 second pause

This error code appears in:

HP Elitedesk 800 G1 Small Form Factor PC