!
error HP
Error Code Power LED blinks red, 10 blinks with a pause
Bad card slot option detected.
? What Causes This
Faulty hardware or improperly installed expansion card.
✓ How to Fix It
Remove affected card and test system. Replace faulty component, re-enable if necessary.
Source: page 2 of the official manual
From the manual
This error code appears in:
HP Prodesk 600 G1 Small Form Factor PC